According to National Statistics Office (NSO) as of 2010, over 92% of the population were Christians, with 80.6% professing Roman Catholicism. The latter was introduced by the Spanish beginning in 1521, and during their 300-year colonization of the islands, they managed to convert a vast majority of Filipinos, resulting in the Philippines becoming the largest Catholic country in Asia. There are also large groups of Protestant denominations, which either grew or were founded following the disestablishment of the Catholic Church during the American Colonial period. The Iglesia ni Cristo is currently the single largest church whose headquarters is in the Philippines, followed by United Church of Christ in the Philippines. The Iglesia Filipina Independiente (also known as the Aglipayan Church) was an earlier development, and is a national church directly resulting from the 1898 Philippine Revolution. Other Christian groups such as the Victory Church, Jesus Miracle Crusade, Mormonism, Orthodoxy, and the Jehovah's Witnesses have a visible presence in the country.