World Muslim Population Report

The projections presented in this report are the medium figures in a range of three scenarios – high, medium and low – generated from models commonly used by demographers around the world to forecast changes in population size and composition. The models follow what is known as the cohort-component method, which starts with a baseline population (in this case, the current number of Muslims in each country) divided into groups, or cohorts, by age and sex.

via World Muslim Population Report – Pew Research Center.