1. Each employer’s contributions to the system shall be the total of the contribution amounts provided for in subsections 2 through 5 of this section; provided, that such contributions shall be subject to the provisions of subsection 6 of this section.

2. An employer’s normal cost contributions shall be determined as follows: using the financial assumptions adopted by the board from time to time, the actuary shall annually compute the rate of contributions which, if paid annually by each employer during the total service of its members, will be sufficient to provide the pension reserves required at the time of their retirements to cover the pensions to which they might be entitled or which might be payable on their behalf. The board shall annually certify to the governing body of each employer the amount of membership service contribution so determined, and each employer shall pay such amount to the system during the employer’s next fiscal year which begins six months or more after the date of such board certification. Such payments shall be made in such manner and form and in such frequency and shall be accompanied by such supporting data as the board shall from time to time determine. When received, such payments shall be credited to the employer’s account in the employer accumulation fund.

3. An employer’s accrued service contributions shall be determined as follows: using the financial assumptions adopted by the board from time to time, the actuary shall annually compute for each employer the portions of pension reserves for pensions which will not be provided by future normal cost contributions. The accrued service pension reserves so determined for each employer less the employer’s applicable balance in the employer accumulation fund shall be amortized over a period of years, as determined by the board. Such period of years shall not extend beyond the latest of (1) forty years from the date the political subdivision became an employer, or (2) thirty years from the date the employer last elected to increase its optional benefit program, or (3) fifteen years from the date of the annual actuarial computation. The board shall annually certify to the governing body of each employer the amount of accrued service contribution so determined for the employer, and each employer shall pay such amount to the system during the employer’s next fiscal year which begins six months or more after the date of such board certification. Such payments shall be made in such manner and form and in such frequency and shall be accompanied by such supporting data as the board shall from time to time determine. When received, such payments shall be credited to the employer’s account in the employer accumulation fund.

4. The employer’s contributions for the portions of disability pensions or pensions that result from a member’s death that was the natural and proximate result of a personal injury or disease arising out of and in the course of his or her actual performance of duty as an employee not covered by accrued service pension reserves shall be determined on a one-year term basis. The board may determine different rates of contributions for employers having policeman members or having fireman members or having neither policeman members nor fireman members. The board shall annually certify to the governing body of each employer the amount of contribution so ascertained for the employer, and each employer shall pay such amount to the system during the employer’s next fiscal year which begins six months or more after the date of such board certification. Such payments shall be made in such manner and form and in such frequency and shall be accompanied by such supporting data as the board shall from time to time ascertain. When received, such payments shall be credited to the casualty reserve fund.

5. Each employer shall provide its share, as determined by the board, of the administrative expenses of the system and shall pay the same to the system to be credited to the income-expense fund.

6. The employer’s total contribution to the system, expressed as a percent of active member compensations, in any employer fiscal year, beginning with the second fiscal year that the political subdivision is an employer, shall not exceed its total contributions for the immediately preceding fiscal year, expressed as a percent of active member compensations, by more than one percent.