(a) The liability of each subscriber, other than as to a nonassessable policy, for the obligations of the reciprocal insurer shall be an individual, several, and proportionate liability, and not joint.
(b) Except as to a nonassessable policy each subscriber shall have a contingent assessment liability, in the amount provided for in the power of attorney or in the subscribers' agreement, for payment of actual losses and expenses incurred while his policy was in force. Such contingent liability may be at the rate of not less than one nor more than ten times the premium or premium deposit stated in the policy, and the maximum aggregate thereof shall be computed in the manner set forth in section twenty of this article.
(c) Each assessable policy issued by the insurer shall contain a statement of the contingent liability, set in type of the same prominence as the insuring clause.