Catholicism – 18 million Various denominations that self-identify as Catholic, despite not being affiliated with the Catholic Church. Philippine Independent Church – 6 million (in communion with the Anglican Communion) Chinese Patriotic Catholic Association – 5 million Apostolic Catholic Church – 5 million Traditionalist Mexican-American Catholic Church – 2 million Brazilian Catholic Apostolic Church – 0.56 million Old Catholic Church – 0.1 million (in communion with the Anglican Communion) Polish National Catholic Church – 0.03 million Palmarian Catholic Church – 0.002 million Protestantism – 900 million–1 billion Protestantism is the second largest major group of Christians by number of followers. Estimates vary from 800 million to 1 billion, or between 31% and 38% of all Christians. The main reason for this wide range is the lack of a common agreement among scholars as to which denominations constitute Protestantism. For instance, most sources but not all include Anabaptism, Anglicanism, Baptists and Independent Nondenominational Christianity as part of Protestantism. Moreover, Protestant denominations altogether do not form a single structure comparable to the Catholic Church, or to a lesser extent the Eastern Orthodox communion. However, several different comparable communions exist within Protestantism, such as the World Evangelical Alliance, Anglican Communion, World Communion of Reformed Churches, World Baptist Alliance, World Methodist Council and the World Lutheran Federation. Regardless, 900 million is the most accepted figure among various authors and scholars, and thus is used in this article. Note that this 900 million figure also includes Anglicanism, as well as Anabaptists, Baptists and multiple other groups that might sometimes disavow a common "Protestant" designation, and would rather prefer to be called, simply, "Christian". Historical Protestantism – 300–500 million The number of individuals who are members of historical Protestant Churches totals to 300-500 million. Anglicanism – 110 million There are about 110 million Christians in Anglican tradition, mostly part of the Anglican Communion, the third-largest Christian communion in the world, with 42 members (provinces). Anglican Communion – 85 million Church of England – 25.0 million Church of Nigeria – 20.1 million Church of Uganda – 8.1 million Anglican Church of Kenya – 5.0 million Church of South India – 3.8 million Province of the Episcopal Church of South Sudan – 3.5 million Anglican Church of Australia – 3.1 million Anglican Church of Southern Africa – 2.3 million Anglican Church of Tanzania – 2.0 million Episcopal Church in the United States – 1.7 million Church of North