(or roughly persons). The descendants of the Ottoman Roma today are known as Xoraxane Roma and are of the Islamic faith. Russians Russians in Turkey number about 50,000 citizens. Russians began migrating to Turkey during the first half of the 1990s. Most were fleeing the economic problems prevalent after the dissolution of the Soviet Union. During this period, many Russian immigrants intermarried and assimilated with Turkish locals, giving rise to a rapid increase in mixed marriages. There is a Russian Association of Education, Culture and Cooperation which aims to expand Russian language and culture in Turkey as well as promote the interests of the community. Serbs In the 1965 Census 6,599 Turkish citizen spoke Serbian as a first language and another 58,802 spoke Serbian as a second language. Zazas The Zazas are a people in eastern Turkey who natively speak the Zaza language. Their heartland, the Dersim region, consists of Tunceli, Bingöl provinces and parts of Elazığ, Erzincan and Diyarbakır provinces. Their language Zazaki is a language spoken in eastern Anatolia between the rivers Euphrates and Tigris. It belongs to the northwest-Iranian group of the Iranian language branch of the Indo-European language family. The Zaza language is related to Kurdish, Persian and Balōchi. An exact indication of the number of Zaza speakers is unknown. Internal Zaza sources estimate the total number of Zaza speakers at 3 to 6 million. Religious minorities Atheists In Turkey, Atheism is the biggest group after Islam. The percentage of atheists according to polls apparently rose from about 2% in 2012 to approximately 3% in 2018 KONDA Survey. Bahá'í Turkish cities Edirne and İstanbul are in the holy places of this religion. Estimate Bahá'í population in Turkey is 10,000 (2008) Christians Christianity has a long history in Anatolia which, nowadays part of the Republic of Turkey's territory, was the birthplace of numerous Christian Apostles and Saints, such as Apostle Paul of Tarsus, Timothy, St. Nicholas of Myra, St. Polycarp of Smyrna and many others. Two out of the five centers (Patriarchates) of the ancient Pentarchy were located in present-day Turkey: Constantinople (Istanbul) and Antioch (Antakya). All of the first seven Ecumenical Councils which are recognized by both the Western and Eastern churches were held in present-day Turkey. Of these, the Nicene Creed, declared with the First Council of Nicaea (İznik) in 325, is of utmost importance and has provided the essential definitions of present-day Christianity. Today