(a) If at any time the assets of a domestic mutual insurer are less than its liabilities and the minimum amount of surplus required to be maintained by it under this title for authority to transact the kinds of insurance being transacted and the deficiency is not cured from other sources, its directors may, if the same is approved by the Commissioner as being reasonable and in the best interests of the insurer and its members, levy an assessment only on its members who held the policies providing for contingent liability at any time within the 12 months next preceding the date the levy was authorized by the board of directors, and such members shall be liable to the insurer for the amount so assessed.
(b) The levy of assessment shall be for such an amount as is required to cure such deficiency and to provide a reasonable amount of working funds above such minimum amount of surplus, but such working funds so provided shall not exceed 5% of the sum of the insurer's liabilities and such minimum required surplus as of the date of the levy.
(c) As to the respective policies subject to the levy, the assessment shall be computed upon the basis of premium earned during the period covered by the levy.
(d) No member shall have an offset against any assessment for which such member is liable, on account of any claim for unearned premium or loss payable.
(e) As to life insurance, any part of such an assessment upon a member which remains unpaid following notice of assessment, demand for payment, and lapse of a reasonable waiting period as specified in such notice, may, if approved by the Commissioner as being in the best interests of the insurer and its members, be secured by placing a lien upon the cash surrender values and accumulated dividends held or to be held by the insurer to the credit of the member's policy.