The measure of the tax on all coal products severed from the ground in this state shall be:
(1) On or after July 1, 2009, through June 30, 2011, fifty cents (50¢) per ton;
(2) On or after July 1, 2011, through June 30, 2013, seventy-five cents (75¢) per ton; and
(3) On or after July 1, 2013, one dollar ($1.00) per ton.