Chiapas has one of the largest and most diverse indigenous populations with approximately 959,066 indigenous language speakers over the age of five, or 27% of the states population. It is home to nine major ethnicities and was a center of Mayan Empire with ceremonial city centers in Palenque and Yaxchiln. However, it is second only to Oaxaca in both indigenous population size and that populations marginality in terms of socio-economic development. Ironically, Chiapas is also one of the states with the most diverse resource base, and the generator of 35% of Mexicos electricity through hydropower. The history of Chiapas indigenous peoples is different from other parts of Mexico in that much of the state was a frontier, that has only recently been settled and freed from a long period of relatively lawless exploitation by diverse interests. It is only in the highlands that indigenous territories were left alone. Elsewhere, many indigenous communities had their territories expropriated to establish commercial estates and were either converted to indentured labor or fled to frontier areas to create new settlements. With colonization has come a number of indigenous populations from neighboring states with different traditions and customs.