 The next four largest metropolitan areas in Mexico are Greater Guadalajara (4.1 million), Greater Monterrey (3.7 million), Greater Puebla (2.1 million) and Greater Toluca (1.6 million), whose added population, along with Greater Mexico City, is equivalent to 30% of the nation's population.Greater Mexico City was the fastest growing metropolitan area in the country since the 1930s until the late 1980s.Since then, the country has slowly become economically and demographically less centralized.