The signing of the Act of Barahona in December 1991 provided for the establishment of a free trade zone by January 1, 1992 and the definition of a common external tariff with four levels (from 5 percent to 20 percent). Since the signing of this Act, Bolivia, Colombia, Ecuador, Peru and Venezuela have progressively established a free trade area. Colombia, Ecuador and Venezuela have implemented a common external tariff (CET). Bolivia has maintained its national tariff schedule, and Peru is subject to transitional arrangements whereby its trade is regulated through bilateral agreements.