You must not be reading my posts, I never said that NHCLC said that 94% of Mexicans fleeing to America were Catholic, only that they had been baptized by Catholics.
I also said that the Pew I see gives 70% of foreign born Hispanics in America as currently Catholic, not as having been so the day they fled Mexico.
Many Mexicans leave the Catholic denomination after escaping Mexico.
But it does illustrate how the stats can be confusing: for instance, how does the CIA World Book get that figure of 87% Catholic in Mexico? Parish active membership rolls? Baptismal records? Responses to a telephone survey? Is it on the Mexican census form?
And when they come here --- is somebody accurately polling the religious affiliation of the subset of Mexicans (6.1 million they're saying as of April 2012?) that's in the US illegally?
You see the overall point: it's not an exact science, this calculating of faith membership.
Many Mexicans escape the Catholic denomination after leaving Mexico.