The employer annuity accumulation fund shall be the account:

1. (1) In which shall be recorded the reserves on all employee annuities in force and against which shall be charged all employee annuities and all benefits in lieu of employee annuities;
2. (2) In which must be recorded all reserves for the payment of all employer annuities and other benefits payable from contributions made by employers and against which is charged all employer annuities and other benefits on account of members with prior service credit; and

3. (3) In which shall be recorded the reserves on all employer annuities granted to members not entitled to prior service credit and against which such employer annuities and benefits in lieu thereof shall be charged.

   There shall be paid to the System and credited to the employer annuity accumulation fund contributions by the employers in an amount equal to a certain percentage of the earnable compensation of each member employed by each employer to be known as the "normal contribution" and an additional amount equal to a percentage of such earnable compensation to be known as the "accrued liability contribution." The rate per cent of such contributions shall be fixed on the basis of the liabilities of the system as shown by actuarial valuation.