The Pew Research Center has been compiling a number of recent reports, answering key questions about Muslims.

• There were 1.6 billion Muslims in the world as of 2010 – roughly 23% of the global population
   
• Although many countries in the Middle East-North Africa region are heavily Muslim, the region is home to only about 20% of the world’s Muslims
   
• In 2015, there were 3.3 million Muslims of all ages in the U.S., or about 1% of the U.S. population
   
• Our Pew's demographic projections estimate that Muslims will make up 2.1% of the U.S. population by the year 2050
   
• The two major factors behind the rapid projected growth of Islam are:
   
  • Muslims have more children than members of other religious groups. Around the world, each Muslim woman has an average of 3.1 children, compared with 2.3 for all other groups combined
     
  • Muslims are the youngest (median age of 23 years old in 2010) of all major religious groups, seven years younger than the median age of non-Muslims. As a result, a larger share of Muslims already are, or will soon be, at the point in their lives when they begin having children
     
• Perceptions of Muslims varied across European nations:
   
  • Majorities in Hungary, Italy, Poland and Greece say they view Muslims unfavorably
     
  • Negative attitudes toward Muslims are much less common in France, Germany, the United Kingdom and elsewhere in Northern and Western Europe
     
  • People who place themselves on the right side of the ideological scale are much more likely than those on the left to see Muslims negatively

The full report can be found on the Pew Research Center website.