Every person engaged in the business of severing oil from the earth shall pay a license
tax of $0.50 per $100.00 of base year gross receipts from the sale of oil severed
in the county. Such gross receipts shall be computed based on the fair market value
of the severed oil at the time the oil is used or sold for use in the county, or,
if not used in the county, at such time as the oil is placed in transit for shipment
out of the county. All persons severing oil and all common carriers transporting such
oil shall be required to maintain records for five years showing the quantities of
and receipts from oil which they have severed or transported; these records shall
be made available to the commissioner of the revenue and the county's license inspector
upon request.