text: I've been wondering that very same thing.  It's not like they fill out a survey or even report themselves on a census.  Someone in the immigration forum even went so far as to say that 96% of them are Mexican!!!  I got a good laugh out of that one!  As if everyone coming up from the south is Mexican!  I guess they don't realize there are other countries below Mexico just as impoverished and willing to travel long ways in terrible conditions to try to find a better life.