Tara Todras-Whitehill, AP
Christian pilgrims pray ahead of the Washing of the Feet ceremony inside the Chapel of St John and Baptistery, in the Church of the Holy Sepulchre, the site where many Christians believe Jesus was crucified and buried, in Jerusalem's Old City, Thursday, April 21, 2011.

Christians now number more than 2 billion around the world, but unlike 100 years ago, they're no longer heavily concentrated in Europe. Instead, the bulk of Christians can be found in the Americas, sub-Saharan Africa and Asia Pacific.

A report issued this week by Pew Research Center's Forum on Religion & Public Life, Global Christianity, shows that while the total number of Christians has grown from 600 million in 1910 to more than 2 billion in 2010, the percentage of the world's Christians in Europe has dropped from 66 percent to 25 percent.

Now, five of the top 10 countries with the largest Christian populations are in Africa and Asia — Nigeria, Democratic Republic of Congo and Ethiopia, the Philippines and China.

(It's difficult to accurately estimate China's Christian population due to the "mix of government-sanctioned churches and grassroots house churches that operate illegally underground," according to the Washington Post.)

The report also shows that sub-Saharan Africa has seen the fastest growth in the number of Christians, skyrocketing from 8.5 million in 1910 to more than 516 million in 2010.

Another Pew Forum on Religion & Public Life study from last April looked at the number of Muslims and Christians in Africa, finding that both groups have grown exponentially and even harmoniously during the last 100 years. Muslims in the area increased from 11 million to nearly 234 million in 2010.

"The vast majority of people in many sub-Saharan African nations are deeply committed to the practices and major tenets of one or the other of the world's two largest religions, Christianity and Islam," the report details. "Large majorities say they belong to one of these faiths, and, in sharp contrast with Europe and the United States, very few people are religiously unaffiliated."

However, the Americas, including Central and South America, still have an estimated 804 million Christians — the largest amount in the world and 36. 8 percent of the world's Christian population.

The global nature of Christianity can be seen quite strikingly through the fact that the birthplace of Christianity — the Middle East-North Africa region — has the smallest number of Christians at only 13 million.

The newest study relied on census data and general population surveys from 232 countries and territories. The data can't measure practice or belief, however. It just counts individuals as Christians if they say they are.

The report calculates that half the world's Christians are Catholic, 37 percent are Protestants, and 12 percent are Orthodox. The remaining 1 percent belong to other traditions, such as Mormonism, according to the Chicago Tribune.