The school board or board of education of any school district may establish a contingency fund for losses. Such contingency fund shall be established and maintained by transfers from the general fund of such school district as authorized by the school board or board of education of such school district. Disbursements from such contingency fund shall not exceed five percent of the total budgeted general fund expenditures of the school district and shall be used only for defense against losses, payment of losses, and transfer of funds to the general fund of such school district as authorized by the board.