Conversation so far:
How did the indigenous develop their cities while under the restrictions of non-indigenous people?
CANNOTANSWER.
How did the economic work?
The indigenous population participate in the workforce longer than the national average, starting earlier and continuing longer.
Are there any other interesting aspects about this article?
Literacy rates are much lower for the indigenous, particularly in the southwestern states of Guerrero and Oaxaca.

Question: How come?
Self-contained rewrite: How come literacy rates are much lower for the indigenous?