With a population density of only 12 inhabitants per sq. kilometer, the state is home to 2'394,861 residents, 30% of which are concentrated in the capital city of Hermosillo, and another 15% in the Cajeme municipality. Other regions reporting high numbers of inhabitants are Nogales, San Luis Rio Colorado and Navojoa. The last census, dating back to the year 2005, reveals that 55% of the state population is younger than 30 years of age; those over 15 years have in average finished secondary school which implies a schooling rate of almost 9 years; and 4% of that same portion over 15 years of age are illiterate, way below the national average of 8%. Life expectancy for those who happen to be born in Sonora reaches 77,6 years for women and 72,2 years of age for men, and the most common causes of death are heart disease, cancer and diabetes. Even if the state has a strong indigenous past, actual population descending from the original local tribes is scarce to say the least, and only 2% of those older than 5 years of age actually speak an indigenous dialect, the most common of which are the Mayo and the Yaqui.