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.

Question: In what part of Mexico do most of these indigenous peoples live?
Self-contained rewrite: In what part of Mexico do most of the Totonac, Nahua and Teenek (Haustec) groups live?