A Contingent Account is created (1) to facilitate the crediting of regular interest on the amounts in the School Retirement Fund, (2) to fund the adjusted supplemental retirement benefit provided by section 79-947, and (3) to provide an account to cover any special requirements of the School Retirement Fund or the Expense Fund. All income, interest, and dividends derived from the deposits and investments authorized by the School Employees Retirement Act shall be paid into the Contingent Account. The retirement board may accept gifts, devises, and bequests. Any funds which may come into the possession of the retirement system in this manner or which may be transferred from the School Retirement Fund by reason of the lack of a claimant or because of a surplus in any fund or account described in section 79-968, or any other money the disposition of which is not otherwise provided for in the act, shall be credited to the Contingent Account. Any deficit occurring in the School Retirement Fund or in the Expense Fund shall be met by payments to the fund from the Contingent Account. Annually the retirement board shall estimate the amount of money deemed necessary to pay the obligation levied against the Contingent Account, including regular interest. If such amount exceeds the revenue estimated to accrue to the fund for that year, such excess shall be certified to the State Treasurer and shall, on warrant of the Director of Administrative Services, be transferred from funds appropriated by the state for such purpose to the Contingent Account.