Islam has surpassed Roman Catholicism as the world's largest religion, the Vatican newspaper said Sunday. "For the first time in history, we are no longer at the top: Muslims have overtaken us," Monsignor Vittorio Formenti said in an interview with the Vatican newspaper L'Osservatore Romano. Formenti compiles the Vatican's yearbook. He said that Catholics accounted for 17.4 percent of the world population - a stable percentage - while Muslims were at 19.2 percent. "It is true that while Muslim families, as is well known, continue to make a lot of children, Christian ones on the contrary tend to have fewer and fewer," the monsignor said.