Tex. Insurance Code - Not Codified § 5.04

(a) To insure the adequacy and reasonableness of rates the Board may take into consideration past and prospective experience, within and outside the State, and all other relevant factors, within and outside the State, gathered from a territory sufficiently broad to include the varying conditions of the risks involved and the hazards and liabilities assumed, and over a period sufficiently long to insure that the rates determined therefrom shall be just, reasonable and adequate, and to that end the Board may consult any rate making organization or association that may now or hereafter exist.

(b) As a basis for motor vehicle rates under this subchapter, the State Board of Insurance shall use data from within this State to the extent that the data is credible and available.

(c) Notwithstanding Subsections (a) and (b) of this article, on and after the effective date of S.B. No. 14, Acts of the 78th Legislature, Regular Session, 2003, rates for personal automobile insurance in this state are determined as provided by Article 5.101 of this code, and rates for commercial motor vehicle insurance in this state are determined as provided by Article 5.13-2 of this code. On and after December 1, 2004, rates for personal automobile insurance and commercial automobile insurance in this state are determined as provided by Article 5.13-2 of this code.