(a) With respect to mortgages approved for insurance under this part prior to January 5, 1976, the initial MIP shall be in an amount equal to one-half percent of the average outstanding principal obligation for the first year of amortization under the mortgage, without taking into account delinquent payments or prepayments.
(b) With respect to mortgages approved for insurance under this part on and after January 5, 1976, the initial MIP shall be in an amount equal to seven-tenths of one percent of the average outstanding principal obligation for the first year of amortization under the mortgage, without taking into account delinquent payments or prepayments.