The contribution of an employer for each fiscal year shall be the percentage of covered payroll approved by the Board on the basis of the most recent actuarial valuation, and shall equal:

1. (1) The normal cost; plus
2. (2) Adjustments for actuarial gains and losses or increases in benefits adopted on or subsequent to participation; plus
3. (3) Administrative costs.

62 Del. Laws, c. 398, § 1