(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, in any case, 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 or she shall receive a lump sum refund of his or her accumulated contributions made under the retirement system to the date of his or her retirement.

(b)

(1) 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 $16.50 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; provided, however, that no benefit increase above $15.00 per month shall be applied to the benefit of persons who were retired on the effective date of this Act. If the General Assembly at any time appropriates funds expressly intended to fund the benefits provided in this subsection and such amount so appropriated is not sufficient to fund the maximum amount allowable, 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 $14.75 multiplied by the member's years of creditable service.

(2) Subject to the terms and limitations of this subsection, the board of trustees is authorized to adopt from time to time a method or methods of providing for increases in the retirement allowance paid up to the maximum benefit provided in paragraph (1) of this subsection. Such method shall be based upon:

(A) The recommendation of the actuary of the board of trustees;

(B) The maintenance of the actuarial soundness of the fund in accordance with the standards provided in Code Section 47-20-10 or such higher standards as may be adopted by the board; and

(C) Such other factors as the board deems relevant.

(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.