Maquiladoras (Mexican factories that take in imported raw materials and produce goods for export) have become the landmark of trade in Mexico. These are plants that moved to this region from the United States, hence the debate over the loss of American jobs. Hufbauer's (2005) book shows that income in the maquiladora sector has increased 15.5% since the implementation of NAFTA in 1994. Other sectors now benefit from the free trade agreement, and the share of exports from non-border states has increased in the last five years while the share of exports from maquiladora-border states has decreased. This has allowed for the rapid growth of non-border metropolitan areas, such as Toluca, León and Puebla; all three larger in population than Tijuana, Ciudad Juárez, and Reynosa.