The map was drawn up based on three WIN/Gallup International surveys conducted in 2008, 2009 e 2015. Each of the interviewees responded “Yes” o “no” when asked if he considers himself religious.
As the map shows, the most religious regions are Africa and the Middle East, although South-East Asia and Latin America are not far behind
The most religious country by far is Ethiopia, where the 99% of the inhabitants consider themselves believers; it should be noted that there are both Christians and Muslims in the country. They have the same percentage of people who declare themselves believers as Malawi, he Niger, Sri Lanka and Yemen. In Somalia the believers are the 98%, in Afghanistan the 97%.

Western Europe, Northern and Central Italy are mostly atheist, even if Poland appears to be out of trend with 86% of people considering themselves religious.

Religion is important in many southern European countries: il 74% of Italians and the 71% Some Greeks consider themselves religious people.
On the other hand, the least religious countries include Japan (13%), Estonia (16%), Sweden (19%), Norway (21%) and the Czech Republic (23%), however China surpasses everyone with only the 7% of believers.
In Russia the 70% of citizens consider themselves religious. In Ukraine this figure is equal to 73%, while for neighboring Belarus the data show a clear discrepancy: only the 34% declares himself a believer. In the United States they are considered religious 56% of the inhabitants.