Over the history of Chiapas, there have been 3 main indigenous groups: the Mixes-Zoques, the Mayas and the Chiapa. Today, there are an estimated fifty-six linguistic groups. As of the 2005 Census, there were 957,255 people who spoke an indigenous language out of a total population of about 3.5 million. Of this one million, one third do not speak Spanish. Out of Chiapas' 111 municipios, 99 have Majority indigenous populations. 22 municipalities have indigenous populations over 90%, and 36 municipalities have native populations exceeding 50%. However, despite population growth in indigenous villages, the percentage of indigenous to non indigenous continues to fall with less than 35% indigenous. Indian populations are concentrated in a few areas, with the largest concentration of indigenous-language-speaking individuals is living in 5 of Chiapas's 9 economic regions: Los Altos, Selva, Norte, Fronteriza, and Sierra. The remaining three regions, Soconusco, Centro and Costa, have populations that are considered to be dominantly mestizo.