(1) To implement the statutory direction to compute an annualized tax rate for class twelve property, the department will employ the procedure outlined in this rule.

(2) The department will obtain the market and taxable value for all commercial, industrial and centrally assessed property from the department's computer data bases or other sources as necessary. � A copy of this information is available to taxpayers upon request.

(3) Upon obtaining the information referred to in (2) , the department will proceed to compute the tax rate reflected in 15-6-145, MCA. � It will employ the mathematical formula reflected in the statute.

(4) In the event that the required information is not available to the department, the taxable value for all commercial, industrial or centrally assessed property will be estimated.

(a) The department will use the reported market and taxable value for all commercial, industrial and centrally assessed property for the previous tax year in estimating the total market value and apply the current taxable percentage to arrive at the current taxable value of all commercial, industrial and centrally assessed property for the present tax year.

(b) This estimation may be challenged by the taxpayer in the event of litigation or in the event of an assessment appeal.

(c) If the department should estimate the class twelve tax rate pursuant to (4) (a) , the department shall review the estimated tax rate by comparing it with the actual class twelve tax rate to be computed by the department no later than September 1 of the present year. � If the actual tax rate varies from the estimated tax rate by more than 5%, the department shall issue revised assessments to the affected property taxpayers pursuant to 15-8-601, MCA.