Calculation of amount of fuel used in Commonwealth. The amount of gasoline or other motor fuel used in the operations of any motor carrier

§ 9607.  Calculation of amount of fuel used in Commonwealth. The amount of gasoline or other motor fuel used in the operations of any motor carrier on highways within this Commonwealth shall be such proportion of the total amount of the gasoline or other motor fuel used in its entire operations within and without this Commonwealth as the total number of miles traveled on highways within this Commonwealth bears to the total number of miles traveled within and without this Commonwealth.