(a) A license issued under this chapter, other than a provisional license, is valid for a term of one or two years as provided by commission rule.
(b) The commission by rule shall adopt a system under which licenses expire on various dates during the year. For a license that is issued for less than a full term, the commission shall prorate license fees on a monthly basis so that the license holder pays only that portion of the license fee that is allocable to the number of months during which the license is valid. On renewal of the license on the new expiration date, the total license renewal fee is payable.