Illegal immigration is falling in Arizona, California and New Mexico, but rising in Pennsylvania and New Jersey, according a study released Wednesday by the Pew Research Center. Drawing on data provided by the U.S. Census, Pew researchers reported a 21 percent increase in the number of people living in Pennsylvania illegally between the years 2009 and 2012. The Keystone State was home to an estimated 170,000 residents here illegally as of 2012, according to the study.