(a) Each member of a domestic mutual insurer, except as otherwise provided in this chapter, shall have a contingent liability, pro rata and not one for another, for the discharge of its obligations. The contingent liability shall be in such maximum amount as is stated in the insurer's articles of incorporation, but shall be not less than one, nor more than five, additional premiums for the member's policy at the annual premium rate and for a term of one year.
(b) Every policy issued by the insurer shall contain a statement of the contingent liability.
(c) Termination of the policy of any such member shall not relieve the member of contingent liability for his proportion of the obligations of the insurer which accrued while the policy was in force.