19(1)Subject to paragraphs 15(3) and 16(3) above, for any financial year, the amount referred to in paragraph 15(1)(b) or paragraph 16(1)(b) above in respect of notional interest on a credit arrangement is that determined by the formula—
where, subject to sub-paragraphs (2) and (3) below,—
“a” is the cost of the arrangement on 1st April in that financial year; and
“b” is the percentage rate of discount prescribed under section 49(2) of this Act for the financial year in which the arrangement came into being or, in the case of a transitional credit arrangement, for the financial year beginning on 1st April 1990.
(2)In the case of a credit arrangement which has been varied as mentioned in section 51(1) of this Act, “b” in the formula in sub-paragraph (1) above is the percentage rate of discount prescribed under section 49(2) of this Act for the financial year in which the arrangement was so varied or, as the case may be, last varied.
(3)In the case of a credit arrangement falling within section 49(3) of this Act, the Secretary of State may by regulations provide that “b” in the formula in sub-paragraph (1) above shall be such figure as may be specified in, or determined under, the regulations.