Upon retirement from service, a member shall receive a retirement allowance as follows:
(1) If the member has met the requirements in section 88-281(a), (b), (d), or (e), a maximum retirement allowance of one and one-fourth per cent of the average final compensation multiplied by the number of years of credited service; or
(2) If the member has met the requirements in section 88-281(c), an early retirement allowance equal to the maximum retirement allowance reduced by one-half per cent for each month the member is less than age sixty-two at retirement.