10. Where, following the amendment made under the former Corporation Tax Act in computing depreciation, a corporation has a difference deductible from its income for a taxation year beginning after 1961, such corporation, to the extent and on the prescribed conditions, may deduct, in each taxation year, in computing its taxable income, the aggregate or a part of such difference, to the extent that it has not yet been deductible from income for years following 1961, according to the rules hereinafter determined:(a) if the difference does not exceed $5,000, the aggregate of such difference;
(b) if the difference exceeds $5,000 but does not exceed $10,000, one-half of such difference;
(c) if the difference exceeds $10,000 but does not exceed $25,000, one-third of such difference;
(d) if the difference exceeds $25,000 but does not exceed $100,000, one-fifth of such difference;
(e) if the difference exceeds $100,000 but does not exceed $1,000,000, one-tenth of such difference; or
(f) if the difference exceeds $1,000,000, one-twelfth of such difference.