(a) The employer shall match all member contributions with a twelve and nine-tenths percent (12.9%) contribution from the fund from which the employees are paid their gross earnings, computed on the basis of the payroll earnings, including overtime and lump-sum payments, of the members of the Arkansas State Highway Employees' Retirement System.

(b) In matching contributions paid under the provisions of § 24-5-108(b), the employer shall match all member contributions for authenticated prior and current service as follows:

(1) Four percent (4%) contribution for service through August 15, 1969;

(2) Six percent (6%) contribution for service from August 15, 1969, to July 1, 1975;

(3) Nine and nine-tenths percent (9.9%) contribution for service from June 30, 1975, to March 20, 1977;

(4) Eleven percent (11%) contribution for service from March 19, 1977, to July 1, 1979;

(5) Twelve and sixty-five-hundredths percent (12.65%) contribution for service from June 30, 1979, to June 25, 1981; and

(6) Twelve and nine-tenths percent (12.9%) contribution for service from June 24, 1981.

(c)

(1) In the event that sufficient money is provided to the system to pay the increase in annuities as authorized by § 24-7-714 from other than the fund from which the employees are paid their gross earnings, then the employer's contribution rate for the then current year shall be twenty-five-hundredths of one percent (0.25%) less than the rate stated in subsection (a) of this section.

(2) In matching contributions under the provisions of § 24-5-108(b), the rate shall be the employer's contribution rate for the then current year.