(a) The commissioner by rule may adopt a system under which licenses expire on various dates during the year.
(b) For a year in which the license expiration date is less than one year from the date of license issuance or the anniversary of that date, the license fee shall be prorated so that each license holder pays only that portion of the license fee allocable to the number of months during which the license is valid. On each subsequent renewal of the license, a license holder must pay the total renewal fee.