(a) Except as otherwise provided by this subsection, an initial registration certificate or license is valid for a period of one year from the date of issue and is renewable on payment of the renewal fee. An initial registration certificate or license issued on or after September 1, 1983, may be issued for a period of less than one year and the renewal fee shall be prorated proportionally.
(b) A renewal of a registration certificate or license issued under this chapter is valid for a period of two years. The license or registration fee for each year of the two-year period is payable on renewal.

(c) The commissioner by rule may adopt a system under which registration certificates and licenses expire on various dates during the year. For the year in which an expiration date of a registration certificate or license is less than one year from its issuance or anniversary date, the fee shall be prorated on a monthly basis so that each holder of a registration certificate or license pays only that portion of the renewal fee that is allocable to the number of months during which the registration certificate or license is valid. On renewal on the new expiration date, the total renewal fee is payable.