, Mexican assembly plants that manufacture finished goods for export to the United States. The maquiladoras are generally owned by non-Mexican corporations. They take advantage of plentiful lower-cost Mexican labor, advantageous tariff regulations (lessened somewhat as a result of the North American Free Trade Agreement), and close proximity to U.S. markets to produce such items as home appliances and automobiles. Starting on a small scale in the mid-1960s, the maquiladoras were initially almost entirely located in the N border region of Mexico. They grew dramatically after Mexico substantially revised its economic regulations concerning foreign investment in the early 1980s. From 1983 to 1990, the maquiladora industry grew at approximately 20% annually, and it grew even more sharply with the U.S. economic boom in the late 1990s; it is one of Mexico's primary sources of foreign exchange. The maquiladoras stimulated rapid population migration to the border region, particularly at its eastern and western extremities (Matamoros/Brownsville and Tijuana/San Diego). After 2000 the number of plants and workers they employed declined; in 2002 some 3,600 plants employed approximately 960,000 workers. Beginning in the late 1990s an increasing number of the plants were located in the Mexican heartland, and many plants now use automation extensively.