(a) Upon the liquidation of a domestic mutual insurer, its assets remaining after discharge of its indebtedness and policy obligations shall be distributed to its members who were such within the 36 months prior to the last termination of its certificate of authority.
(b) The distributive share of each such member shall be in the proportion that the aggregate premiums earned by the insurer on the policies of the member during the combined periods of his membership, bear to the aggregate of all premiums so earned on the policies of all such members. If a life insurer, the insurer shall make a reasonable classification of its life insurance policies so held by such members and a formula based upon such classification for determining the equitable distributive share of each such member. Such classification and formula shall be subject to the Commissioner's approval.