Conversation so far:
How many indigenous peoples are there in Mexico?
According to the National Commission for the Development of the Indigenous Peoples, there were 25,694,928 indigenous people reported in Mexico in 2015,
How many different groups of indigenous peoples are included in the statistics for the number of indigenous people reported in Mexico in 2015?
The category of indigenous can be defined narrowly according to linguistic criteria including only persons that speak one of Mexico's 89 indigenous languages.
In what part of Mexico do most indigenous peoples live?
The majority of the indigenous population of Mexico is concentrated in the central and southern states.
What is the age distribution of the indigenous peoples of Mexico?
Besides the Yucatán, what other Mexican states have a significant indigenous population?
According to the CDI, the Mexican states with the greatest percentage of indigenous population include: Oaxaca with 65.73% of the population; Campeche with 44.54%; Quintana Roo with 44.44%; and more.
Do the indigenous peoples of Mexico tend to live in urban or suburban areas?
The indigenous peoples of Mexico are more likely to live in more rural areas, but many do reside in urban or suburban areas.
What percentage of the indigenous peoples of Mexico live in rural areas?
Besides their geographic distribution, what are some other statistics that are relevant to the indigenous people of Mexico?
The indigenous population of Mexico has in recent decades increased both in absolute numbers as-well as a percentage of the population.

Question: What is the reason for this increase?
Self-contained rewrite: What is the reason for the increase in the indigenous population of Mexico in recent decades?