medium water supplies in the remaining rural areas are the responsibility of the Direction Générale du Génie Rurale (DGGR). In 1974, ONAS was established to manage the sanitation sector. Since 1993, ONAS has had the status of a main operator for protection of water environment and combating pollution. The rate of non-revenue water is the lowest in the region at 21% in 2012. Demographics According to the CIA, as of 2021, Tunisia has a population of 11,811,335 inhabitants. The government has supported a successful family planning program that has reduced the population growth rate to just over 1% per annum, contributing to Tunisia's economic and social stability. Ethnic groups According to the CIA World Factbook, ethnic groups in Tunisia are: Arab 98%, European 1%, Jewish and other 1%. According to the 1956 Tunisian census, Tunisia had a population at the time of 3,783,000 residents, 95% consisting of Berbers and Arabs, 256,000 Europeans and 105,000 Jews. Speakers of Berber dialects were 2% of the population. According to another source, the population of Arabs is estimated to be <40% to 98%, and that of Berbers at 1% to over 60%. Black Tunisians make up 10–15% of the population and are mostly descended from sub-Saharan Africans brought to Tunisia as part of the slave trade. Amazighs are generally concentrated in the Dahar mountains and on the island of Djerba in the southeast, and in the Khroumire mountainous region in the north-west. An important number of genetic and other historical studies point to the predominance of the Amazighs in Tunisia. An Ottoman influence has been particularly significant in forming the Turco-Tunisian community. Other peoples have also migrated to Tunisia during different time periods, including West Africans, Greeks, Romans, Vandals, Phoenicians (Punics), Jews, and French and Italian settlers. By 1870, the distinction between the Arabic-speaking population and the Turkish elite had blurred. From the late 19th century to the period after World War II, Tunisia was home to large populations of French and Italians (255,000 Europeans in 1956), although nearly all of them, along with the Jewish population, left after Tunisia became independent. The history of the Jews in Tunisia goes back some 2,000 years. In 1948, the Jewish population was estimated at 105,000, but by 2013 only about 1000 remained. The first people known to history in what is now Tunisia were the Berbers. Numerous civilizations and peoples have invaded, migrated to, or have