(a) Management and Sales Types and Investor Sponsored Projects.

1. (1) If the date of the first principal payment is more than one year following the date of such initial insurance endorsement, the mortgagee, upon the anniversary of such insurance date, shall pay a second premium equal to one-half of one percent of the original face amount of the mortgage. On the date of the first principal payment, the mortgagee shall pay a third premium equal to one-half of one percent of the average outstanding principal obligation of the mortgage for the following year which shall be adjusted so as to accord with such date and so that the aggregate of the first, second and third premiums shall equal the sum of:

   1. (i) One percent of the average outstanding principal obligation of the mortgage for the year following the date of initial insurance endorsement, and
   2. (ii) One-half of one percent per annum of the average outstanding principal obligation of the mortgage for the period from the first anniversary of the date of initial insurance endorsement to one year following the date of the first principal payment.

2. (2) If the date of the first principal payment of a mortgage is more than one year following the date of the initial insurance endorsement and the mortgage is paid in full prior to the date of such first principal payment, the first and second premiums collected shall be adjusted so that the aggregate of the two premiums shall equal the sum of:

   1. (i) One percent of the average outstanding principal obligation of the mortgage for the year following the date of the initial insurance endorsement and
   2. (ii) One-half of one percent per annum of the average outstanding principal obligation of the mortgage for the period from the first anniversary of the date of initial endorsement to the date the mortgage was paid in full.