(1) For tax periods beginning on and after July 1, 2009, at the time of filing the return required by section 66-488, the producer, supplier, distributor, wholesaler, or importer shall, in addition to the other taxes provided for by law, pay a tax at the rate of five percent of the average wholesale price of gasoline for the gallons of the motor fuels as shown by the return, except that there shall be no tax on the motor fuels reported if they are otherwise exempted by sections 66-482 to 66-4,149.
(2) The department shall calculate the average wholesale price of gasoline on April 1, 2009, and on each April 1 and October 1 thereafter. The average wholesale price on April 1 shall apply to returns for the tax periods beginning on and after July 1, and the average wholesale price on October 1 shall apply to returns for the tax periods beginning on and after January 1. The average wholesale price shall be determined using data available from the State Energy Office and shall be an average wholesale price per gallon of gasoline sold in the state over the previous six-month period, excluding any state or federal excise tax or environmental fees. The change in the average wholesale price between two six-month periods shall be adjusted so that the increase or decrease in the tax provided for in this section or section 66-6,109.02 does not exceed one cent per gallon.
(3) All sums of money received under this section shall be credited to the Highway Trust Fund. Credits and refunds of such tax allowed to producers, suppliers, distributors, wholesalers, or importers shall be paid from the Highway Trust Fund. The balance of the amount credited, after credits and refunds, shall be allocated as follows:
(a) Sixty-six percent to the Highway Cash Fund for the Department of Transportation;
(b) Seventeen percent to the Highway Allocation Fund for allocation to the various counties for road purposes; and
(c) Seventeen percent to the Highway Allocation Fund for allocation to the various municipalities for street purposes.