HER MAJESTY THE QUEEN,
REASONS FOR JUDGMENT
 These appeals are from assessments for the appellant's 1992, 1993 and 1994 taxation years. The facts are not disputed and the point in issue is a narrow and somewhat technical one.
 The appellant was an employee of the House of Commons. He suffers from a heart condition and diabetes. He was hospitalised in 1988. He applied for and received benefits from the Long Term Disability Plan of the House of Commons (the Public Service Management Insurance Plan, or PSMIP). The plan is funded by the employer and the employee. The carrier is National Life Assurance Company of Canada (National Life).
 In addition to the benefits under the PSMIP the appellant applied for and received Canada Pension Plan disability benefits. The CPP benefits reduced the amounts that he was entitled to receive under the PSMIP.
 The appellant left Canada in 1989 for reasons that had to do with the quality of health care in Canada as well as the availability of heart transplants in the United States. He was given five years to live but that prognosis has obviously been proved wrong. He continues to be a non-resident of Canada.
 In 1993, National Life, based on a report by a medical person who had never seen the appellant and who looked only at the file, discontinued his benefits under the PSMIP. He sued and ultimately had the benefits reinstated.
 After the settlement with National Life, the Canada Customs and Revenue Agency wrote to the appellant demanding that returns be filed for 1991, 1992, 1993, 1994 and 1995.
 The appellant filed returns for 1992, 1993 and 1994. Assessments were issued.
 In computing his income for those years the appellant reported Wage Loss Replacement Plan benefits received under the PSMIP in the amounts of $29,870.00, $30,542.00 and $23,307.00 respectively, as well as $6,943.00, $7,068.00 and $7,202.00 received from the CPP.
 He also claimed non-refundable tax credits for each of the years in the following amounts: basic personal amount: $6,456.00; spousal amount: $5,380.00; pension income amount: $1,000.00; disability amount: $4,233.00. He claimed as well non-refundable tax credits for medical expenses in the amounts of $20,971.00; $16,048.00 and $18,123.00 respectively. Also, he claimed $5,900.00 for charitable donations in 1992.
 On assessing on October 9, 1997 for 1992, 1993 and 1994, the Minister of National Revenue deleted the amount of the CPP disability payments from income and disallowed all of the non-refundable tax credits except for the disability amount. The result was that tax of $6,859.68, $7,064.75 and $5,025.99 was assessed for those years.
 On November 10, 1997, the Minister reassessed and applied the provisions of Article XVIII of the Canada-U.S. Income Tax Convention (1980). This had the effect of limiting the tax for those years to 15% of the Wage Loss Replacement Plan benefits, or $4,480.50, $4,581.30 and $3,496.05.
 Counsel for the respondent in her written submissions states that the issue is whether the CPP payments are caught by paragraph 6(1)(f) of the Income Tax Act so that they are considered to be income from an office or employment. I agree that that is the principal issue. There is, however, a secondary issue with respect to the question whether, even if the CPP payments are not income from an office or employment, "all or substantially all of his income is included in computing his taxable income in Canada."
 The second issue arises only if I decide the first issue in favour of the respondent. This would require a decision that the CPP payments are not income from an office or employment.
 As a non-resident, the appellant is subject to tax under Part I of the Income Tax Act on income earned in Canada. Subsection 2(3) reads
Where a person who is not taxable under subsection (1) for a taxation year
(a) was employed in Canada,
(b) carried on a business in Canada, or
(c) disposed of a taxable Canadian property,
at any time in the year or a previous year, an income tax shall be paid as hereinafter required upon his taxable income earned in Canada for the year determined in accordance with Division D.
Subparagraph 115(1)(a)(i) provides
For the purposes of this Act, the taxable income earned in Canada for a taxation year of a person who at no time in the year is resident in Canada is the amount of his income for the year that would be determined under section 3 if
(a) he had no income other than
(i) incomes from the duties of offices and employments performed by him in Canada,
Paragraph 6(1)(f) reads
There shall be included in computing the income of a taxpayer for a taxation year as income from an office or employment such of the following amounts as are applicable:
. . . . .
(f) the aggregate of amounts received by him in the year that were payable to him on a periodic basis in respect of the loss of all or any part of his income from an office or employment, pursuant to
(i) a sickness or accident insurance plan,
(ii) a disability insurance plan, or
(iii) an income maintenance insurance plan
to or under which his employer has made a contribution, not exceeding the amount, if any, by which
(iv) the aggregate of all such amounts received by him pursuant to the plan before the end of the year and
(A) where there was a preceding taxation year ending after 1971 in which any such amount was, by virtue of this paragraph, included in computing his income, after the last such year, and
(B) in any other case, after 1971,
(v) the aggregate of the contributions made by the taxpayer under the plan before the end of the year and
(A) where there was a preceding taxation year described in subparagraph (iv), after the last such year, and
(B) in any other case, after 1967;
 The respondent's position is that the amounts received from National Life under the Wage Loss Replacement Plan fall squarely within paragraph 6(1)(f) because they are paid pursuant to a disability insurance plan under which the appellant's employer has made a contribution. By way of contrast, the respondent argues that the CPP payments do not fall under paragraph 6(1)(f) because the CPP is not an insurance plan at all; it is a pension plan. She contends that the CPP payments are more in the nature of social security benefits and she relies upon some observations made in Hausmann Estate v. Canada,  4 C.T.C. 2232.
 Counsel further supports her argument by reference to paragraph 56(1)(a) which reads in part
56. (1) Without restricting the generality of section 3, there shall be included in computing the income of a taxpayer for a taxation year,
(a) any amount received by the taxpayer in the year as, on account or in lieu of payment of, or in satisfaction of,
(i) a superannuation or pension benefit including, without limiting the generality of the foregoing.
(A) the amount of any pension, supplement or spouse's allowance under the Old Age Security Act and the amount of any similar payment under a law of a province,
(B) the amount of any benefit under the Canada Pension Plan or a provincial pension plan as defined in section 3 of that Act,
She argues that the specific provisions of paragraph 56(1)(a) override the more general provision of paragraph 6(1)(f).
 On this point despite the extremely thorough and persuasive written argument presented by Mr. Watts, I agree with counsel for the respondent. It is true that at least where the recipient of CPP benefits was an employee both the employer and the employee must contribute. Nonetheless, I should not have thought that one could regard the social security regime of which the CPP is so integral a part in Canada as an insurance plan. Insurance has been defined in different ways but I am not aware of any definition that would encompass a government-run pension plan. As Stone, J.A. observed in Consolidated-Bathurst Ltd. v. The Queen,  1 C.T.C. 55 at page 63:
. . . insurance involves risk shifting and risk distributing.
In Re Bendix Automotive Ltd. and U.A.W., Local 195,  3 O.R. 263, Pennell, J. referred to a number of definitions of insurance. He said at pages 268-9:
There are many other definitions of insurance appearing in textbooks and cases, all of which are essentially the same as that found in the Insurance Act. It would perhaps be helpful at this point to set out some of these definitions to illustrate their similarity.
In Prudential Insurance Co. v. Commissioners of Inland Revenue,  2 K.B. 658, Channell, J., at p. 663, described a contract of insurance as follows:
It must be a contract whereby for some consideration, usually but not necessarily for periodical payments called premiums, you secure to yourself some benefit, usually but not necessarily the payment of a sum of money, upon the happening of some event. Then the next thing that is necessary is that the event sould be one which involves some amount of uncertainty. There must be either uncertainty whether the event will ever happen or not, or if the event is one which must happen at some time there must be uncertainty as to the time at which it will happen. The remaining essential is that which was referred to by the Attorney-General when he said the insurance must be against something. A contract which would otherwise be a mere wager may become an insurance by reason of the assured having an interest in the subject-matter - that is to say, the uncertain event which is necessary to make the contract amount to an insurance must be an event which is prima facie adverse to the interest of the assured.
In passing, I note that this last essential was modified by the Court of Appeal in Gould v. Curtis,  3 K.B. 84, per Cozens-Hardy, M.R., at p. 92.
Jenks, A Digest of English Civil Law, 3rd ed. (1938), at p. 285, defines insurance as follows:
705. A contract of insurance is a contract whereby one party ("the insurer") agrees with another ("the insured"), in consideration of a payment or series of payments ("premium"), to pay to the latter or to his representatives or nominee a sum or sums of money conditionally on death or the happening of any uncertain event, which it is contemplated will or may cause loss or expense to the insured or such nominee ('interest" or "insurable interest").
Another judicial definition may be found in a judgment of Lawrence, J., in Lucena v. Craufurd (1806), 2 Bos. & Pul. (N.R.) 269 at p. 301, 127 E.R. 630:
. . . insurance is a contract by which the one party in consideration of a price paid to him adequate to the risk, becomes security to the other that he shall not suffer loss, damage, or prejudice by the happening of the perils specified to certain things which may be exposed to them.
Counsel for the applicant also relied upon Livingstone v. Western Assurance Co. (1868), 14 Gr. 461, per Spragge, V.-C., at p. 463; reversed by 16 Gr. 9, but without affecting the passage cited, and Mitchell v. City of Toronto (1921), 50 O.L.R. 585 at p. 592, 64 D.L.R. 569 at pp. 574-5, per Hodgins, J.A., dissenting. No purpose would be served by quoting from these cases which in essence set out similar definitions to those above quoted.
The basic elements which are common to all of these definitions may be stated as follows:
i) an undertaking of one person;
ii) to indemnify another person;
iii) for an agreed consideration;
iv) from loss or liability in respect of an event;
v) the happening of which is uncertain.
 Insurance is essentially a contractual arrangement between an insured and an insurer and involves an obligation by an insurer, upon payment of premiums, to pay an amount upon an event whose occurrence is uncertain. The statutory regime administered by the CPP contains none of those elements. The payments under it are therefore not income from an office or employment as described in paragraph 6(1)(f) of the Income Tax Act. Rather, they are taxable as income by reason of paragraph 56(1)(a).
 The right of Canada to tax these two types of payments is limited by the Canada-U.S. Income Tax Convention, (1980), Article XVIII reads in part as follows
1. Pensions and annuities arising in a Contracting State and paid to a resident of the other Contracting State may be taxed in that other State, but the amount of any such pension that would be excluded from taxable income in the first-mentioned State if the recipient were a resident thereof shall be exempt from taxation in that other State.
(a) pensions may also be taxed in the Contracting State in which they arise and according to the laws of that State; but if a resident of the other Contracting State is the beneficial owner of a periodic pension payment, the tax so charged shall not exceed 15 per cent of the gross amount of such payment; and
(b) annuities may also be taxed in the Contracting State in which they arise and according to the laws of that State; but if a resident of the other Contracting State is the beneficial owner of an annuity payment, the tax so charged shall not exceed 15 per cent of the portion of such payment that would not be excluded from taxable income in the first-mentioned State if the beneficial owner were a resident thereof.
3. For the purposes of this Convention, the term "pensions" includes any payment under a superannuation, pension or retirement plan, Armed Forces retirement pay, war veterans pensions and allowances and amounts paid under a sickness, accident or disability plan, but does not include payments under an income-averaging annuity contract or any benefit referred to in paragraph 5.
4. For the purposes of the Convention, the term "annuities" means a stated sum paid periodically at stated times during life or during a specified number of years, under an obligation to make the payments in return for adequate and full consideration (other than services rendered), but does not include a payment that is not a periodic payment or any annuity the cost of which was deductible for the purposes of taxation in the Contracting State in which it was acquired.
5. Benefits under the social security legislation in a Contracting State paid to a resident of the other Contracting State shall be taxable as follows:
(a) such benefits shall be taxable only in that other State;
(b) notwithstanding the provisions of subparagraph (a), one-half of the total amount of any such benefit paid in a taxable year shall be exempt from taxation in that other State.
 I have omitted the technical explanations of each of these provisions. The result is that the Wage Loss Replacement Plan payments by National Life are caught by paragraph 6(1)(f) of the Income Tax Act. Moreover, they fall within the definition of pension as provided in paragraph 3 of Article XVIII of the Canada-U.S. Income Tax Convention (1980) and Canada may therefore tax them. Under paragraph 2 of Article XVIII, Canada's right to tax is limited to 15%.
 So far as the CPP payments are concerned, they are, by reason of paragraph 5 of Article XVIII, taxable only in the United States because they are, in my view, benefits under the social security legislation of Canada.
 I have concluded therefore that the Wage Loss Replacement Plan payments are income from an office or employment and are subject to tax by Canada at 15%. The CPP payments received by the appellant, a non-resident, are not taxable by Canada.
 Section 118.94 of the Income Tax Actreads as follows
Sections 118 and 118.2, subsections 118.3(2) and (3) and sections 118.6, 118.8 and 118.9 do not apply for the purpose of computing the tax payable under this Part for a taxation year by an individual who at no time in the year is resident in Canada unless all or substantially all of the individual's income for the year is included in computing the individual's taxable income earned in Canada for the year.
The remaining question therefore is whether all or substantially all of the appellant's income is included in computing his taxable income earned in Canada. Counsel for the respondent argues that for 1993 and 1994 if the CPP payments are excluded from the appellant's income, the answer to the question is no.
 The appellant's income from the two sources as declared in his income tax return was
Year 1992 1993 1994
(a) Wage Loss Replacement Benefits $29,870 $30,542 $23,307
(b) CPP $_6,943 $ 7,068 $ 7,202
(c) Total $36,813 $37,610 $30,509
(d) Percentage that (a) is of (c) 81.139% 81.207% 76.309%
 However, in attachments to his income tax return he stated that his world income was slightly different for 1992, 1993 and 1994 - $34,309.00; $39,624.00 and $31,157.00, respectively. If I accepted these numbers it would change the percentages to 87%, 77% and 74.8%. The Crown has conceded the appellant's position for 1992 with respect to the medical expenses but not with respect to the pension amount (because of his age). Do the differences in the percentages justify a different treatment for 1993 and 1994? I shall proceed upon the basis that the correct percentages are 81.139%, 81.207% and 76.309%. These figures result from a comparison of the Wage Loss Replacement Plan benefits with the aggregate of those benefits and the CPP payments. There is simply no evidence of any additional income (or of its nature) in 1993 and 1994 or any loss for 1992 from other sources. There is no assumption pleaded with respect to income or loss from other sources.
 There has been a fair amount written about the somewhat imprecise term "all or substantially all". The unofficial departmental position is 90% but the meaning of the expression should not be decided on the basis of an arbitrary percentage.
 In Pronovost v. The Queen, 2003 TCC 139, it was observed that
 In Ruhl (W.) v. Canada,  G.S.T.C. 4, and in Lim (J.H.) v. Canada,  G.S.T.C. 1, the meaning of "substantial" or "substantially all" was considered. In Ruhl it was observed that they are terms of some elasticity and that "an unsatisfactory medium for carrying the idea of some ascertainable proportion of the whole. They do not require a strictly proportional or quantitative determination".
 The 90% rule used by the CCRA has no statutory basis although it may be necessary that some sort of rigid criterion be applied administratively. That does not mean that the court must follow it. The 90% rule, even if it had some basis in law, is itself defective because it leaves unanswered the question "90% of what? time? mileage? number or weight of passengers or goods carried?"
 In Lim v. The Queen, I commented further on the meaning of "substantial" or "substantial completion"
 I shall, however, deal briefly with the concept of "substantial completion". The words "substantial" or "substantially" appear in a number of statutes, including the Income Tax Act and mechanics' lien statutes of the provinces. They have been the subject of a certain amount of judicial commentary. Their meaning in a particular statute has often occasioned some difficulty. The terms are somewhat flexible and relative, and their meaning is derived from the context in which they are used and the facts of the particular case.
 It is useful to read what Viscount Simon said in Palser v. Grinling,  A.C. 291 at pages 316-317:
(5.) What does "substantial portion" mean? It is plain that the phrase requires a comparison with the whole rent, and the whole rent means the entire contractual rent payable by the tenant in return for the occupation of the premises together with all the other covenants of the landlord. "Substantial" in this connexion is not the same as "not unsubstantial," i.e., just enough to avoid the "de minimis" principle. One of the primary meanings of the word is equivalent to considerable, solid, or big. It is in this sense that we speak of a substantial fortune, a substantial meal, a substantial man, a substantial argument or ground of defence. Applying the word in this sense, it must be left to the discretion of the judge of fact to decide as best he can according to the circumstances in each case, the onus being on the landlord. If the judgment of the Court of Appeal in Palser's case were to be understood as fixing percentages as a legal measure, that would be going beyond the powers of the judiciary. To say that everything over 20 per cent. of the whole rent should be regarded as a substantial portion of that rent would be to play the part of a legislator : if Parliament thinks fit to amend the statute by fixing percentages, Parliament will do so. Aristotle long ago pointed out that the degree of precision that is attainable depends on the subject matter. There is no reason for the House to differ from the conclusion reached in these two cases that the portion was not substantial, but this conclusion is justified by the view taken on the facts, not by laying down percentages of general application.
 The Department of National Revenue uses the percentage of 90% as a test to determine substantial completion. As an administrative rule of thumb it may well be a commendable attempt to add some precision to an imprecise concept, but it is difficult to apply in practice. One question that arises is: 90% of what? time? money? appearance? I think we should bear in mind Viscount Simon's admonition about the use of percentages.
 The term has been considered in other cases, notably Australian. In A. E. Terry's Motors Ltd. v. Rinder,  S.A.S.R. 167 at 180, Mayo J. said
'What is meant by "a substantial part" and "the remaining part" of the premises? "Substantial" is not a word with a fixed meaning in all contexts. In certain associations it can be taken to stress the quality of solidarity or strength. It may be related to the appearance of some physical object. With other concepts it may refer to weight, volume, or area. Again it may be used to indicate worth, or stability. Used in a comparative setting, "a substantial part" as against "the remaining part", it suggests a dichotomy into the substantial part, and the not-substantial, a contrast, according to cubic contents, or area, between the greater and the less, as between the essential and the subordinate or incidental. In his satiric view of the modern use of language entitled What a Word, A P Herbert treats "substantial" in a quantitative sense, as the modern colloquial equivalent of "much" or even "some". It is an unsatisfactory medium for carrying the idea of some ascertainable proportion of the whole.'
Similarly, Deane J. in Tillmanns Butcheries Pty. Ltd. v. Australasian Meat Industry Employees' Union and Others,(1979) 42 F.L.R. 331 at 348, said
'The word "substantial" is not only susceptible of ambiguity: it is a word calculated to conceal a lack of precision. In the phrase "substantial loss or damage", it can, in an appropriate context, mean real or of substance as distinct from ephemeral or nominal. It can also mean large, weighty or big. It can be used in a relative sense or can indicate an absolute significance, quantity or size. The difficulties and uncertainties which the use of the word is liable to cause are well illustrated by the guidance given by Viscount Simon in Palser v Grinling [supra] where, after holding that, in the context there under consideration, the meaning of the word was equivalent to "considerable, solid or big", he said: "Applying the word in this sense, it must be left to the discretion of the judge of fact to decide as best he can according to the circumstances of each case." . . . In the context of s 45D(1) of the [Trade Practices] Act 1974-1986 (Cth), the word "substantial" is used in a relative sense in that, regardless of whether it means large or weighty on the one hand or real or of substance as distinct from ephemeral or nominal in the other, it would be necessary to know something of the nature and scope of the relevant business before one could say that particular, actual or potential loss or damage was substantial. As at present advised, I incline to the view that the phrase, substantial loss or damage, in s 45(D)(1) includes loss or damage that is, in the circumstances, real or of substance and not insubstantial or nominal.'
 I think it would be absurd to conclude that the appellant's rights under the Income Tax Act should depend on the assignment of an arbitrary percentage to the words "all or substantially all". This mechanical exercise runs counter to common sense.
 In Re Olympia & York and Hiram Walker, 59 O.R. (2d) 254, Montgomery J. quoted with approval from a case from the Delaware Chancery Court, Gimbel v. Signal Companies, Inc., 316 A.2d 599 at pp. 605 and 608 as follows
. . . Again, it is not necessary to go beyond the statute. The statute requires shareholder approval upon the sale of "all or substantially all" of the corporation's assets. That is the sole test to be applied. While it is true that the test does not lend itself to a strict mathematical standard to be applied in every case, the qualitative factor can be defined to some degree notwithstanding the limited Delaware authority. But the definition must begin with and ultimately necessarily relate to our statutory language.
Montgomery J. then went on to say
It is fallacious to suggest that when a holding company that has three distinct divisions and sells one of three divisions for 2.6 billion dollars out of a total worth of six billion dollars, it could possibly fall within s. 183(3).
His judgment was affirmed by the Ontario Divisional Court.
 I mention parenthetically that in Gimbel, the Delaware Chancery Court referred to another Delaware Chancery decision of Philadelphia National Bank v. B.S.F. Co., 41 Del.Ch. 509, in which the Court held that 75% of a corporation's assets constituted "substantially all" of its assets.
 There are many cases in this Court that have considered the meaning of "all or substantially all". They consistently comment on the elasticity and ambiguity of the expression and on the inadvisability of using an arbitrary percentage, such as 90%. For example, Rip J. in McDonald v. The Queen, 98 DTC 2151 stated at p. 2154
 The word "substantially" is not defined in dictionaries as a fixed portion of a whole. The so-called "90% rule" is a rule of thumb that is no doubt convenient to assessors and tax advisors in determining a reasonable standby charge.
 The Oxford English Dictionary defines "substantially" to mean, among other things,
b. essentially, intrinsically
c. actually, really
 The same dictionary defines the word "substantial" to include "of ample or considerable amount, quantity or dimensions."
 In the French version of subsection 6(2), the words "all or substantially all" are "la totalité, ou presque". The word "presque" is defined by Le Petit Robert as "à peu près". The Collins-Robert French-English, English-French Dictionary does not include the words "substantial" or "substantially" in the English meaning of the word "presque". The words included are: "almost" and "nearly". The word "substantially" is translated in Collins-Robert as "considérablement" in the context of "considerably" and "en grande partie" when the word "substantially" means "to a large extent".
 These dictionary definitions confirm that the word "substantially", as Bowman, J.T.C.C. remarked in Ruhl v. Canada, is elastic and an unsatisfactory medium for conveying the concept of an ascertainable proportion of the whole. The words "substantially all" in the context of paragraph 6(2)(d) need not be interpreted as 90% or more but may be a lesser proportion of the whole depending on the facts. In the case at bar, at least 85% of the distance travelled was in connection with Mr. McDonald's employment and in my view that is substantially all of the distance travelled by the automobile in the total days it was available to Mr. McDonald.
 See also Keefe v. M.N.R., 2003 DTC 1526, where Sheridan J. held that 81% was "all or substantially all". In the following cases 80% has held to be "all or substantially all". McKay v. R., 2000 G.S.T.C. 93 and Ruhl (W.) v. Canada,  G.S.T.C. 4.
 The difference between 81, 77 and 76 (or 81, 81 and 76) percent is not large enough to justify a different treatment in the three years. In the circumstances of this case the amounts received as Wage Loss Replacement Plan benefits under the PSMIP represent substantially all of his income for the three years.
 The appeals are allowed and the assessments are referred back to the Minister of National Revenue for reconsideration and reassessment in accordance with these reasons. The appellant is entitled to his costs, if any, in accordance with the tariff.
Signed at Ottawa, Canada, this 19th day of August 2004.