Definitions; determination of valuation of commercial vehicle for ad valorem tax purposes.

(a) As used in this Code section, the term:

(1) “Georgia fleet mileage ratio” means a fraction, the numerator of which is the total miles driven in Georgia by all commercial vehicles registered in Georgia under the International Registration Plan pursuant to Code Section 40-2-88, and the denominator of which is the total miles driven within and without Georgia by such commercial vehicles.

(2) “Gross capital cost” means the freight on board, delivered cost of a commercial vehicle to the purchaser of such commercial vehicle but shall not include any excise or use taxes paid as a part of such purchase.