Sec. 406.072.  PRINCIPAL LOCATION.  The principal location of a person's employment is where:
(1)  the employer has a place of business at or from which the employee regularly works;  or
(2)  the employee resides and spends a substantial part of the employee's working time.
Acts 1993, 73rd Leg., ch. 269, Sec. 1, eff. Sept. 1, 1993.