A mutual life insurance company may not issue a policy until not less than two hundred thousand dollars of insurance in not less than two hundred separate risks have been subscribed for and entered on its books. The commissioner may not issue a certificate of authority for the transaction of business to the company unless it has a surplus of assets over all liabilities of at least one million dollars. A domestic mutual life insurance company shall maintain surplus of at least this amount. However, for any company doing business only in this state, if the minimum asset and surplus requirements required by this section are more than the minimum requirements required at the time a company was issued its original certificate of authority, the company shall increase its assets and surplus to a minimum of one hundred thousand dollars. All other companies shall increase their surplus of assets over all liabilities according to the schedule set out in subsection 4 of section 26.1-12-08.