(a) Any member may retire and upon application to the board receive the retirement benefits set forth in this Code section after obtaining a minimum of ten years of creditable service. The effective date of retirement shall be the first of the month in which the application is received by the board, provided that no retirement application will be effective earlier than the first of the month following the final month of the applicant's employment. If a member retires before obtaining ten years of creditable service, he shall receive a lump sum refund of his accumulated contributions made under the retirement system to the date of his retirement.

(b) Upon retirement on the normal retirement date, a member shall receive a monthly retirement benefit, payment of which shall commence on the effective date of retirement and which shall be payable on the first day of each month thereafter during the member's lifetime. The amount of each monthly retirement payment shall be $12.00 multiplied by the number of the member's years of creditable service. The retirement benefit provided under this subsection shall be payable to those members who have already retired under this chapter as well as those members who retire in the future. If the General Assembly at any time appropriates some but not all of the funds necessary to fund the retirement benefits provided for in this subsection, then the retirement benefit otherwise payable under this subsection shall be reduced pro rata by the board in accordance with the funds actually appropriated by the General Assembly for such purpose, but in no event shall the retirement benefit be less than $9.50 multiplied by the member's years of creditable service.

(c) Upon retirement on his delayed retirement date, a member shall receive a monthly retirement benefit, payment of which shall commence on his delayed effective date of retirement and which shall be payable on the first day of each month thereafter during his lifetime. The amount of each monthly retirement benefit shall be computed in the same manner as for a normal retirement benefit and shall be based on the number of years of creditable service as of the member's delayed retirement date.

(d) Any member who exercises his right to retire at an early retirement date pursuant to subsections (c) through (e) of Code Section 47-4-100 shall receive a monthly retirement benefit which shall begin on the early effective date of retirement. Such benefit shall be payable on the first day of each month thereafter during his lifetime. The amount of each monthly retirement benefit shall be computed in the same manner as for a normal retirement benefit and shall be based on the number of years of creditable service as of the member's early retirement date, provided that such benefit shall be actuarially reduced at the rate of one-half of 1 percent for each full month that such member is under 65 years of age.