1999: an amount equivalent to one-sixth of each of the deferred revenue (meaning the amount remaining after deducting, from the amount of revenue from that instalment sale under the transitional rules, the amount of revenue that would be included in gross revenue for the year in which the instalment sale under the transitional rules was made if that amount of revenue were accounted for under the instalment basis method; the same applies hereinafter in this paragraph) and the deferred expenses (meaning the amount remaining after deducting, from the amount of expenses from that instalment sale under the transitional rules, the amount of expenses that would be included in necessary expenses for the year in which the instalment sale under the transitional rules was made if that amount of expenses were accounted for under the instalment basis method; the same applies hereinafter in this paragraph);