(a) Except as provided by Section 912.308, this section applies only to an insurance company that:
(1) writes insurance only in this state; and
(2) is not required by law to have capital stock.
(b) Notwithstanding any other provision of this subchapter other than Sections 822.212(b) and (c), an insurance company must have a minimum amount of unencumbered surplus or a minimum amount of guaranty fund and unencumbered surplus equal to the greater of:
(1) the amount of unencumbered surplus or the amount of guaranty fund and surplus, as appropriate, the company was required to have on August 31, 1991; or
(2) one-third of the company's net written premium for the preceding 12 months after deducting:
(A) lawfully ceded reinsurance; and
(B) any policy fees not ceded to reinsurers.