(ABC News) -- With 1 billion Catholics worldwide, the face of the church is changing.
It's something the cardinal electors may keep in mind when the conclave to elect a new pontiff begins in late March, said Matthew Bunson, general editor of the Catholic Almanac and author of "We Have a Pope! Benedict XVI."
The 117 cardinals who are eligible to vote for the new pontiff hail from approximately 50 different countries, and they almost always elect one of their own.
Joseph Ratzinger, an intellectual and respected cardinal from Germany, was the frontrunner for the papacy in 2005, Bunson said. When elected, he became Pope Benedict XVI.
This year, there are no strong favorites.
"The door, in a way, is very much open," Bunson said.
Take a quick look at some of the possible picks for pope in the slideshow.