When a member retires after July 1 and has previously received a retirement allowance for one or more full fiscal years, the retired member shall be eligible immediately for the additional benefit. The additional benefit shall be based on the current retirement allowance and the number of full fiscal years in retirement and shall be prorated and paid in monthly installments based on the number of months a retirement allowance is paid during the fiscal year.
27 Miss. Code. R. 210-58-106