VATICAN CITY (Reuters) – Islam has overtaken Roman Catholicism as the biggest single religious denomination in the world, the Vatican said on Sunday. Monsignor Vittorio Formenti, who compiled the Vatican’s newly-released 2008 yearbook of statistics, said Muslims made up 19.2 percent of the world’s population and Catholics 17.4 percent. “For the first time in history we are no longer at the top: the Muslims have overtaken us,” Formenti told Vatican newspaper L’Osservatore Romano in an interview, saying the data referred to 2006.