Acts 1965, 59th Leg., vol. 2, p. 317, ch. 722. Amended by Acts 1973, 63rd Leg., p. 984, ch. 399, Sec. 2(E), eff. Jan. 1, 1974.

Amended by Acts 1981, 67th Leg., p. 2789, ch. 755, Sec. 3, eff. Sept. 1, 1981.

Amended by:

Acts 2017, 85th Leg., R.S., Ch. 174 (H.B. 3237), Sec. 2, eff. May 26, 2017.