Mexico City reports 8,7 million inhabitants according to recent statistics contained in the national census carried out during the year 2005, as well as a population density of 5,799 persons per sq. km., which means it concentrates roughly 8% of the national total. Even more, when grouped with portions of the neighboring states of Mexico and Hidalgo, it conforms the largest metropolitan area in the country, with a population of approximately 25 million people. Life expectancy for those being born in the state is located at 73 years of age for men and 78 years for women, higher than the national average. On the other hand, 3% of the adults residing in the state did not attend school, and the average schooling for those over 15 years of age is of 10,2 years, which in fact means that generally speaking they are better prepared than the rest of Mexicans. In terms of migration, this crowded district said fare-well to over 400,000 citizens during the year 2005, which, contrary to tendencies in the past decades, decided to move on to other states in the republic. Other demographic particulars include the facts that as much as 91% of the population declares to be Catholic, and that only 2% of its population speaks an indigenous dialect, of which the Nahautl, Otomi, Zapoteco and Mixteco are the most common.