The amount set aside for vacancy and collection loss reserves at the end of each calendar quarter shall be equal to three per cent, or such other rate as the division shall approve or prescribe, of the total dwelling rent schedule (account 3110) for such quarter less actual dwelling vacancy losses incurred (account 3111) and collection losses (account 4770) written off during such quarter. For the purpose of this provision, total dwelling rent schedule shall be the sum of the following:

The amount set aside for any project shall not increase the accumulated total reserve for vacancy and collection losses to an amount greater than the highest total dwelling rent schedule, as defined above, for any full calendar quarter between the end of the initial operating period and March 31, 1947, for projects whose date of substantial completion is prior to March 31, 1947, or greater than the highest total dwelling rent schedule for any full calendar quarter up to and including the eighth quarter after the end of the initial operating period, for projects whose date of substantial completion is subsequent to March 31, 1947. A full calendar quarter consists of a consecutive three month period ending March 31, June 30, September 30 or December 31.