Acts 1965, 59th Leg., p. 456, ch. 233, Sec. 1, eff. Aug. 30, 1965. Amended by Acts 1971, 62nd Leg., p. 1818, ch. 542, Sec. 8, eff. Sept. 1, 1971; Acts 1981, 67th Leg., p. 571, ch. 237, Sec. 44, eff. Sept. 1, 1981; Acts 1991, 72nd Leg., ch. 597, Sec. 11, eff. Sept. 1, 1991; Acts 2001, 77th Leg., ch. 669, Sec. 156, eff. Sept. 1, 2001.

Amended by:

Acts 2011, 82nd Leg., R.S., Ch. 1163 (H.B. 2702), Sec. 187, eff. September 1, 2011.