40% of the total population. The Javanese are concentrated on the island of Java but millions have migrated to other islands throughout the archipelago because of the transmigration program. The Sundanese, Malays, Batak, Madurese, Betawi, and Minangkabau are the next largest groups in the country. Many ethnic groups, particularly in Kalimantan and Papua, have only hundreds of members. Most of the local languages belong to Austronesian language family, although a significant number, particularly in Maluku Islands and Western New Guinea belong to Papuan languages. The Chinese Indonesians (Tionghoa) population makes up a little less than 1% of the total Indonesian population according to the 2000 census. Some of these Indonesians of Chinese descent speak various Chinese languages, most notably Hokkien and Hakka. The classification of ethnic groups in Indonesia is not rigid and in some cases unclear due to migrations, cultural and linguistic influences; for example, some may consider Osing people and Cirebonese to be members of Javanese people, however, some others argue that they are different ethnic groups altogether since they have their own distinct dialects. This is the same case with Baduy people that actually are sub-ethnic of the Sundanese people but sometimes considered as separated ethnicities. An example of hybrid ethnicity is the Betawi people, descended not only from marriages between different peoples in Indonesia but also with foreign origin like Arab, Chinese and Indian migrants since the era of colonial Batavia (Jakarta). Language Indonesian is the official language of Indonesia. It is a standardized variety of Malay, an Austronesian language that has been used as a lingua franca in the Indonesian archipelago for centuries. Most Indonesians also speak one of more than 700 indigenous languages. Most Indonesians, aside from speaking the national language, are fluent in another regional language (examples include Javanese, Sundanese and others), which are commonly used at home and within the local community. Most formal education, and nearly all national media and other forms of communication, are conducted in Indonesian. In East Timor, which was an Indonesian province from 1975 to 1999, Indonesian is recognised by the constitution as one of the two working languages (the other being English), alongside the official languages of Tetum and Portuguese. Literature Indonesian literature can refer to literature produced in the Indonesian archipelago. It is also used to refer more broadly to literature produced in areas with common language roots based on the Malay language (of which