Another four instances of non-paternity were found among male descendants, but researchers believed their fathers were probably among the early island population. There are eighty families on the island. Language Tristan da Cunha's isolation has led to development of its own accent. In popular writing, it has been described by the writer Simon Winchester as "a sonorous amalgam of Home Counties lockjaw and 19th century idiom, Afrikaans slang and Italian." Unique features of "Tristan da Cunha English" include the non-diphthongization of the vowel of (such as that "face" is pronounced ), and h-insertion in words like "[h]apple" and "[h]after" (such as that "island" and "highland" are homonyms). Education Children leave school at age 16, and although they can take GCSEs a year later, few do. The school on the island is St. Mary's School, which serves children from ages 4 to 16. The Naval Station had established a school building during World War II. The current facility opened in 1975 and has five classrooms, a kitchen, a stage, a computer room, and a craft and science room. Tristan students doing post-16 education receive assistance from the Tristan da Cunha Association Education Trust Fund and typically do so in the United Kingdom and South Africa. The Tristan Song Project was a collaboration between St. Mary's School and amateur composers in Britain, led by music teacher Tony Triggs. It began in 2010 and involved St. Mary's pupils writing poems and Triggs providing musical settings by himself and his pupils. A desktop publication entitled Rockhopper Penguins and Other Songs (2010) embraced most of the songs completed that year and funded a consignment of guitars to the school. In February 2013, the Tristan Post Office issued a set of four Song Project stamps featuring island musical instruments and lyrics from Song Project songs about Tristan's volcano and wildlife. In 2014, the project broadened its scope and continues as the International Song Project. Religion The only religion is Christianity, with the only denominations being Anglican and Roman Catholic. The Roman Catholic population is served by the Mission Sui Iuris of Saint Helena, Ascension, and Tristan da Cunha, which is administratively a part of the Apostolic Prefecture of the Falkland Islands. Edwin Dodgson, youngest brother of Lewis Carroll, spent several years as a missionary on the island in the nineteenth century. Health Healthcare is funded by the government, undertaken at most times by one resident doctor.