There shall be maintained, within the contingency reserve fund, a segregated portion to be known as the variable contingency reserve fund, the purpose of which shall be to accumulate such assets as may be necessary to effect the net transfers from the contingency reserve fund to the variable annuity reserve fund and the variable pension reserve fund, as required by subdivision a of section 13-577 of this chapter. The actuary shall prepare an annual estimate of the assets necessary to make such future adjustments with respect to all benefits to be provided out of the current assets of the variable annuity funds other than the variable contingency reserve fund. Such estimate shall be based on the mortality experienced among beneficiaries of the annuity reserve fund and pension reserve fund number one, as shown by the most recent actuarial investigation pursuant to section 13-514 of this chapter. When, in accordance with a determination by the actuary, there is sufficient experience in the operation of the variable annuity program, the estimate shall recognize the mortality experienced among participating beneficiaries. The assets of the variable contingency reserve fund shall be maintained at a level as nearly as possible consistent with such estimates.