Of the 570 municipalities of Oaxaca, 417 elect their authorities by usos y costumbres, “uses and customs,” the Indigenous customary systems. This is according to the Electoral Tribunal of the Federal Judiciary.
The state recognized these systems on August 30, 1995, when its Congress added a book on them to the state electoral code. The number has varied over time: 412 municipalities in 1995, 418 in 1998 and 417 in 2013.