So far as it applies in relation to a period of account of the lessor beginning before 1 January 2005, the definition of “bad debt deduction” in section 911(6) applies with the substitution for “the total” onwards of “ the total of any sums falling within sub-paragraph (i), (ii) or (iii) of section 74(1)(j) of ICTA in respect of amounts in respect of rents from the lease of the asset which are deductible as expenses for that period ”.