For the purposes of paying the costs and expenses incurred in connection with the administration and enforcement of the oil and gas conservation laws of the State of Mississippi and of the rules, regulations and orders of the State Oil and Gas Board, there is levied and assessed against each barrel of oil produced in the State of Mississippi a charge not to exceed sixty (60) mills on each barrel of such oil sold, and against each one thousand (1,000) cubic feet of gas produced and sold a charge not to exceed six (6) mills on each one thousand (1,000) cubic feet of gas. The State Oil and Gas Board shall fix the amount of such charge in the first instances, and may, from time to time, change, reduce or increase the amount thereof, as in its judgment the charges against the fund may require, but the amounts fixed by the board shall not exceed the limits hereinabove prescribed; and it shall be the duty of the board to make collection of such assessments. All monies collected shall be used exclusively to pay the expenses and other costs in connection with the functioning of the State Oil and Gas Board and the administration of the oil and gas conservation laws of the State of Mississippi now in force or hereafter enacted and the rules, regulations and orders of the board.