From vdare.com:
What does the Mexican government do with child illegal aliens? According to a report in Mexico’s El Universal, in 2013 there were 9,893 illegal alien minors detained in Mexico. Of that total, 8,350 (84% of the total) were deported while only 50 were granted official refugee status. The remainder, numbering 1,493 were neither deported nor given refugee status, but apparently allowed to join family members (of varying legal statuses) who were already in the country of Mexico.
I’m guessing too, that there were more than 9,893 passing through, but that’s the quantity that was caught and officially registered.