This is the largest study of its kind. I don't know if they also have forthcoming surveys regarding religiosity and science attitudes. Nevertheless, this demographic work is of immense importance. Here are some of the key findings (helpfully extracted by Faithworld from the Pew Executive Summary):
There are 1.57 billion Muslims of all ages in the world today, about 23 percent of the global population of 6.8 billion. (By contrast, various estimates put the number of Christians worldwide at about two billion).
- Over 60 percent of Muslims live in Asia and one-fifth in the Middle East and North Africa.
- More than 300 million Muslims, or one-fifth of their global population, live in countries where Islam is not the majority religion. Muslims are a minority in India but it has the third-largest Muslim population (161 million).
- Sub-Saharan Africa has about 15 percent of the Muslim population, and Pew estimates that Muslims are a slight majority in Nigeria at 50.4 percent of the population.
- Ten to 13 percent of Muslims are estimated to be Shias and most Shias live in just four countries: Iran, Pakistan, India and Iraq. Sunnis account for 87 to 90 percent of the Muslim population.
- In Europe, there are an estimated 38.1 million Muslims.