The allowable maximum weight (license class) for which a truck or tractor is registered may be decreased only once a year, at the beginning of a new license year. Trucks classified in divisions (a)(3)(A)(i), (a)(3)(A)(ii), (a)(3)(A)(iii), (a)(10)(A)(i), (a)(10)(A)(ii), and (a)(10)(A)(iii) of Code Section 48-10-2 shall not be entitled to any partial year license.