15-31-307. Values used for property factor. (1) Property owned by the taxpayer is valued at its original cost. Property rented by the taxpayer is valued at 8 times the net annual rental rate. The net annual rental rate is the annual rental rate paid by the taxpayer less any annual rental rate received by the taxpayer from subrentals.
(2) The average value of property shall be determined by averaging the values at the beginning and ending of the tax period, but the tax administrator may require the averaging of monthly values during the tax period if reasonably required to reflect properly the average value of the taxpayer's property.