A comprehensive demographic study of more than 200 countries finds there are 1.57 billion Muslims of all ages living in the world today, representing 23% of an estimated 2009 world population of 6.8 billion. A series of interactive maps show the size and distribution of the worldwide Muslim population.
If current trends continue, the population of the United States will rise to 438 million in 2050, from 296 million in 2005, and 82% of the increase will be due to immigrants arriving from 2005 to 2050 and their U.S.-born descendants, according to new projections developed by the Pew Research Center.
A growing number of Americans believe that immigrants are a burden to the country, taking jobs and housing and creating strains on the health care system. Many people also worry about the cultural impact of the expanding number of newcomers in the U.S.