Simplify the following text for a Grade 6 native English-speaking person.
Original: A comprehensive 2009 demographic study of 232 countries and territories reported that 23 % of the global population or 1.57 billion people are Muslims .
Simplified: In 2009 , a study was done in 232 countries and territories . This study found that 23 % of the global population or 1.57 billion people are Muslims .