Turkish, Arabic, Kurdish and Serbo-Croatian are heard more often in the western part, due to the large Middle Eastern and former-Yugoslavian communities. Polish, English, Russian, and Vietnamese have more native speakers in East Berlin. According to the 2011 census, approximately 37 percent of the population reported being members of a legally-recognized church or religious organization. The rest either did not belong to such an organization, or there was no information available about them. The largest religious denomination recorded in 2010 was the Protestant regional church body—the Evangelical Church of Berlin-Brandenburg-Silesian Upper Lusatia (EKBO)—a United church. EKBO is a member of the Evangelical Church in Germany (EKD) and Union Evangelischer Kirchen (UEK). According to the EKBO, their membership accounted for 18.7 percent of the local population, while the Roman Catholic Church had 9.1 percent of residents registered as its members. About 2.7% of the population identify with other Christian denominations (mostly Eastern Orthodox, but also various Protestants). According to the Berlin residents register, in 2018 14.9 percent were members of the Evangelical Church, and 8.5 percent were members of the Catholic Church. The government keeps a register of members of these churches for tax purposes, because it collects church tax on behalf of the churches. It does not keep records of members of other religious organizations which may collect their own church tax, in this way. In 2009, approximately 249,000 Muslims were reported by the Office of Statistics to be members of Mosques and Islamic religious organizations in Berlin, while in 2016, the newspaper "Der Tagesspiegel" estimated that about 350,000 Muslims observed Ramadan in Berlin. In 2018, more than 420,000 registered residents, about 11% of the total, reported having a migration background from Islamic countries. Between 1992 and 2011 the Muslim population almost doubled. About 0.9% of Berliners belong to other religions. Of the estimated population of 30,000–45,000 Jewish residents, approximately 12,000 are registered members of religious organizations. Berlin is the seat of the Roman Catholic archbishop of Berlin and EKBO's elected chairperson is titled the bishop of EKBO. Furthermore, Berlin is the seat of many Orthodox cathedrals, such as the Cathedral of St. Boris the Baptist, one of the two seats of the Bulgarian Orthodox Diocese of Western and Central Europe, and the Resurrection of Christ Cathedral of the Diocese of Berlin (Patriarchate of Moscow).