Greater Mexico City refers to the conurbation around Mexico City, officially called Mexico City Metropolitan Area (Área Metropolitana de la Ciudad de México), constituted by the Federal District—itself composed of 16 boroughs—and 41 adjacent municipalities of the states of Mexico and Hidalgo. For normative purposes, however, Greater Mexico City most commonly refers to the Metropolitan Area of the Valley of Mexico (Zona Metropolitana del Valle de México) an agglomeration that incorporates 18 additional municipalities. As of 2010 Census, Greater Mexico City had a population just over 20 million, making it the largest metropolitan area in North America followed by the New York metropolitan area. But as of a 2014 census, it's estimated the population of Greater Mexico City at 22.5 million people.