The shapefiles are encoded as codepage 1252 and were reprojected to WGS84. All data corresponds to the 2010 census.
Now for the ugly bits: You’ll need a recent version of innoextract, one that can work with files created by version 5.5 of Inno Setup (yes, the INEGI distributes shapefiles as windows installers), the one in Ubuntu universe is not recent enough. The version available at this repository should work.
sudo add-apt-repository ppa:arx/release
Plus, you’ll also get a bunch of shapefiles of parks, rivers, schools and so on.
P.S. You can contact the INEGI and tell them what you think of the way they distribute data.
P.P.S. If you need shapefiles of elevation curves, archeological sites, rivers, etc, try this other script
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