The Pew numbers conflate completely different sources to deliberately underestimate the net count. For entrants, they count only working head-of-household adults. For exits, they count every single person leaving, even children. They then just subtract the latter from the former. This process understates the net entrants by a factor of at least three. Keep that in mind when quoting Pew, which is an interest group. On their "5 Facts" page, they even say, "the number of unauthorized immigrants living in the U.S. was lower in 2015 than it was at the end of the Great Recession in 2009", which contradicts even their own data, let alone the CIS reference you cite.