All data about demographic information regarding Western Sahara is extremely error-prone, regardless of source. Most countries take censuses every ten years, and some every five in order to stay abreast of change and miscounts; the last count was conducted in 1970, and even that data by colonial Spain is considered unreliable due to large nomadic populations. Following the 1975 Green March, the Moroccan state has sponsored settlement schemes enticing thousands of Moroccans to move into the Moroccan-occupied part of Western Sahara (80% of the territory). By 2015, it was estimated that Moroccan settlers made up at least two thirds of the 500,000 inhabitants. Under international law, Morocco's transfer of its own civilians into Non-Self-Governing territory is in direct violation of Article 49 of the Fourth Geneva Convention (cf. Israeli and Turkish settlers). The religion in Western Sahara is Sunni Islam. The major ethnic groups are Arab and Berbers. The most common language is Arabic. CIA World Factbook demographic statistics The following demographic statistics are from the CIA World Factbook, unless otherwise indicated. Languages Modern Standard Arabic and Spanish, the former colonial language, are the official languages of the Polisario Front, based in Tindouf, Algeria. Hassaniya, an Arabic dialect, is the native language spoken in Western Sahara and in the refugee camps in Tindouf in Algeria. There is also a significant presence of Berber language speakers in the northern parts of the territory of Western Sahara. Hassaniya, primarily spoken at home, is dominated by the Moroccan dialect spoken in the streets, workplace, and schools. This is because the great majority of the population consists of Moroccans who settled in Western Sahara. French is also commonly used by the Moroccan administration. In the urban areas Moroccan Arabic is now spoken, as Morocco controls and administers most of the territory of Western Sahara and all of its cities, and considers it an inseparable part of the country. The Moroccan constitution stipulates two official languages for the Kingdom of Morocco, including Western Sahara: Berber (Tamazight) and Arabic. Spanish is common among Sahrawi people and especially among the Sahrawi diaspora, with the Sahrawi Press Service, official news service of the Sahrawi Arab Democratic Republic, being available in Spanish since 2001 and the Sahara Film Festival, Western Sahara's only film festival, showing mainly Spanish-language films. Spanish is used to document Sahrawi poetry and oral traditions and has also been used in Sahrawi literature. Despite Spanish having