(a) An insurer may refuse to renew a liability insurance or commercial property insurance policy if the insurer delivers or mails written notice of the nonrenewal to the first-named insured under the policy at the address shown on the policy.
(b) The notice must be delivered or mailed not later than the 60th day before the date on which the policy expires. If the notice is delivered or mailed later than the 60th day before the date on which the policy expires, the coverage remains in effect until the 61st day after the date on which the notice is delivered or mailed.
(c) Earned premium for any period of coverage that extends beyond the expiration date of the policy shall be computed pro rata based on the previous year's rate.