Any 911 surcharge revenue collected in excess of the annual fiscal requirements of the board and the mandatory every two (2) months payments to emergency communications districts shall not revert to the general fund. The board shall distribute a minimum of fifty percent (50%) of any revenue collected in excess of its annual fiscal requirements to the emergency communications districts in accordance with policies adopted by the board. Any unspent funds at the end of a fiscal year shall be carried forward to the next fiscal year to be used as a beginning balance of the fiscal requirements for such fiscal year.