(a) Any member who is approved for retirement benefits as provided in Code Section 47-25-80 shall be paid a monthly sum equal to 4 percent of his or her average final monthly compensation for each year served by the member up to, but not exceeding, a total of 20 years; provided, however, that the final annual compensation used for calculating a benefit under this Code section shall not exceed $42,781.22 or the amount fixed in the following schedule according to county population, whichever amount is higher:

Population Maximum Average Final

Monthly Expenses

---------- --------------

500,000 or more $ 7,247.87

400,000 -- 6,975.70

499,999

300,000 -- 6,703.53

399,999

250,000 -- 6,072.65

299,999

200,000 -- 5,594.17

249,999

150,000 -- 5,132.49

199,999

100,000 -- 4,797.70

149,999

75,000 -- 4,490.76

99,999

50,000 -- 4,183.47

74,999

39,000 -- 3,732.53

49,999

29,000 -- 3,512.80

38,999

20,000 -- 3,293.34

28,999

11,890 -- 3,073.88

19,999

6,000 -- 11,889 2,713.53

0 -- 5,999 1,975.98

(b) The board of commissioners is authorized to adopt from time to time a method or methods of providing for increases in the maximum final monthly compensation used for calculating a benefit as provided in this Code section. Such method or methods shall be based upon:

(1) The recommendation of the actuary of the board of commissioners;

(2) 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

(3) Such other factors as the board deems relevant; provided, however, that any such increase shall be uniform and shall apply equally to all members of this retirement system.

No time for which dues have not been paid in accordance with Code Section 47-25-41 shall be considered in determining the number of years of service.