(1) For purposes of auditing for collection of tonnage taxes on coal severed in this state, the Department of Revenue recognizes an inherent moisture content of 2.88% to be included in the tonnage measure of the tax.
(2) Moisture content over and above the 2.88% inherent figure may be allowed as a discount on the tonnage measure, but only if substantiated by a valid laboratory analysis of the moisture content of the coal for the entire audit period, or a substantial portion of the audit period involved. (Effective July 13, 1979)