Eastern Orthodoxy by country
Based on the numbers of adherents, the Eastern Orthodox Church (also known as Eastern Orthodoxy) is the second largest Christian communion in the world after the Roman Catholic Church. The most common estimates of the number of Eastern Orthodox Christians worldwide is approximately 200–260 million. The numerous Protestant groups in the world, if taken all together, outnumber the Eastern Orthodox, but they differ theologically and do not form a single communion.
Religion in Vietnam
Official government records counted 2.2 million registered members of Tây Ninh Cao Đài in 2005, but also estimated in 2007 that there were 3.2 million Caodaists including roughly a dozen other denominations. According to the official statistics, in 2014, the estimated number of Caodaists is 4.4 million, it was a dramatic increase of 1.2 million followers or an increase of 37.5%. Country Information and Guidance — Vietnam: Religious minority groups. December 2014. Quoting United Nations' "Press Statement on the visit to the Socialist Republic of Viet Nam by the Special Rapporteur on freedom of religion or belief". It is more likely that "unofficial" Caodaists have decided that it is now acceptable to identify themselves as followers of the religion in the last seven years. Many outside sources give 4 to 6 million. Some estimates are as high as 8 million adherents in Vietnam. An additional 30,000 (numbers may vary) (primarily ethnic Vietnamese) live in the United States, Europe, and Australia.