At least once in each biennium the administrative board shall cause an actuarial valuation to be made by an actuary who shall certify to the assets and liabilities of the system and the amount of employer's contributions required for membership service and prior service. The cost of the survey shall be paid from any funds available to the Highway Safety Patrol.
On account of each member there shall be paid quarterly into the "Disability and Relief Fund for Members of the Mississippi Highway Safety Patrol" by the Highway Safety Patrol from any funds available an amount equal to a certain percentage of the compensation of each member to be known as the "normal contributions," and an additional amount equal to a percentage of his compensation to be known as the "accrued liability contribution." The rate percent of such contributions shall be fixed by the administrative board on the basis of the liabilities of the retirement system for the various allowances and benefits as shown by the actuarial valuation.