Cameroon is home to at least 250 languages. However, some accounts report around 600 languages. These include 55 Afro-Asiatic languages, two Nilo-Saharan languages, four Ubangian languages, and 169 Niger–Congo languages. This latter group comprises one Senegambian language (Fulfulde), 28 Adamawa languages, and 142 Benue–Congo languages (130 of which are Bantu languages). French and English are official languages, a heritage of Cameroon's colonial past as a colony of both France and the United Kingdom from 1916 to 1961. Eight out of the ten regions of Cameroon are primarily francophone, representing 83% of the country's population, and two are anglophone, representing 17%. The anglophone proportion of the country is in constant regression, having decreased from 21% in 1976 to 20% in 1987 and to 17% in 2005, and is estimated at 16% in 2015 (whose fourth census should take place in 2015). The nation strives toward bilingualism, but in reality very few (11.6%) Cameroonians are literate in both French and English, and 28.8% are literate in neither. The government has established several bilingual schools in an effort to teach both languages more evenly; however, in reality most of these schools separate the anglophone and francophone sections and therefore do not provide a true bilingual experience. Cameroon is a member of both the Commonwealth of Nations and La Francophonie. German, the country's official language during the German colonial period until World War I, has nowadays almost entirely yielded to its two successors. However, as a foreign language subject German still enjoys huge popularity among pupils and students, with 300,000 people learning or speaking German in Cameroon in 2010. Today, Cameroon is one of the African countries with the highest number of people with knowledge of German. Most people in the English-speaking Northwest and Southwest provinces speak Cameroonian Pidgin English, also called Kamtok, as a lingua franca. Fulfulde serves the same function in the north, and Ewondo in much of the Center, South, and East provinces. Camfranglais (or Frananglais) is a relatively new pidgin communication form emerging in urban areas and other locations where Anglophone and Francophone Cameroonians meet and interact. Popular singers have used the hybrid language and added to its popularity. Education for the deaf in Cameroon uses American Sign Language, introduced by the deaf American missionary Andrew Foster. There is little literature, radio, or television programming in native Cameroonian languages. Nevertheless, many Cameroonian languages have alphabets or other writing systems, many