Illegal Immigration Slows Dramatically 2.46K Adrian Chen 09/01/10 11:07PM Filed to: Immigration Immigration Illegal Immigration Numbers Pizza burger The number of immigrants entering the U.S. illegally dropped to 300,000 a year between March 2007 and 2009, down from 850,000 per year between 2000-2005. They took one look at the Pizza Burger and ran the other way.