(a) The premium charged to an insured shall not increase due to either:
(1) Increasing age of the insured at ages beyond sixty-five; or
(2) The duration the insured has been covered under the policy.
(b) The purchase of additional coverage shall not be considered a premium rate increase, but for purposes of the calculation required under section 431:10H-233, the portion of the premium attributable to the additional coverage shall be added to and considered part of the initial annual premium.
(c) A reduction of benefits shall not be considered a premium change, but for purpose of calculation required under section 431:10H-233, the initial annual premium shall be based on reduced benefits.