"The International Migration Review (IMR) today published a study with new estimates of the unauthorized immigrant population. The report, titled Unauthorized Immigration to the United States: Annual Estimates and Components of Change, by State, 1990 to 2010, is co-authored by Robert Warren, former demographer for the US Immigration and Naturalization Service (INS), and John Robert Warren, professor of sociology at the University of Minnesota. It is available here. The report estimates that the number of unauthorized immigrants arriving in the U.S. peaked at more than one million annually between 1999 and 2001, and then declined rapidly thereafter. The number leaving the population steadily increased over these years." - IMR, Feb. 15, 2013.