(a) When applying for a certificate of authority a domestic mutual insurer proposing to transact casualty insurance, including vehicle insurance, must:
(1) Have applications for the insurance in a reasonable amount from at least two hundred and fifty persons covering not less than five hundred separate risks; and
(2) Have collected from each applicant the proper premium for a term of not less than one year at a rate filed with and approved by the commissioner; and
(3) Have a surplus over all liabilities, as at completion of issuance of the insurance contracts so applied for, amounting to not less than $1,500,000.
(b) In lieu of the applications, premiums, and surplus, it is required to have a surplus amounting to not less than $2,250,000 over all liabilities.