Pretty much what I said, but on your numbers you confused the percentage of foreign born Hispanics currently being Catholic in the United States, with what percentage they were on the day they left Mexico, when about 94% of them had been baptized Catholic.
That’s not what I read from the Pew Religion and Public Life survey. They say the number of Catholics has been dropping for decades, and that at this point those coming from Mexico to the US are 70% Catholic. But your stats may vary. Your source?