Conversation so far:
How many indigenous peoples are there in Mexico?
there were 25,694,928 indigenous people reported in Mexico in 2015, which constitutes 21.5% of the population of Mexico.
How many different groups of indigenous peoples are included in those statistics?
Totonac, Nahua and Teenek (Huastec) groups.
In what part of Mexico do most of these indigenous peoples live?
According to the CDI, the states with the greatest percentage of indigenous population are: Yucatan, with 65.40%.
What is the age distribution of indigenous peoples?
CANNOTANSWER.
Besides the Yucutan, what other Mexican states have a significant indigenous population?
Quintana Roo with 44.44% and Campeche with 44.54% of the population being indigenous, most of them Maya; Oaxaca with 65.73% of the population.
Do indigenous peoples tend to live in urban or suburban areas?
Indigenous peoples are more likely to live in more rural areas, than the Mexican average, but many do reside in urban or suburban areas.
What percentage live in rural areas?
CANNOTANSWER.
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 of population of Mexican indigenous people?