From the Mexican census, via Andrew Sullivan:
In 1990, one in five dwellings had a bare-earth floor. Now only 6% do. … More interesting still is what Mexicans put in those homes. More houses have televisions (93%) than fridges (82%) or showers (65%). In a hot country with dreadful television this is curious.
I don’t find this puzzling at all. A lot of Mexico has elevated altitude and many of the homes are open air. Mexican TV is more fun than taking a shower, too.