identity of "Turkestani". In more recent times, religious education is highly restricted in Xinjiang and the Chinese authority had sought to eradicate any religious school they considered illegal. Although Islamic private schools (Sino-Arabic schools ()) have been supported and permitted by the Chinese government among Hui Muslim areas since the 1980s, this policy does not extend to schools in Xinjiang due to fear of separatism. Beginning in the early 20th century, secular education became more widespread. Early in the communist era, Uyghurs had a choice of two separate secular school systems, one conducted in their own language and one offering instructions only in Chinese. Many Uyghurs linked the preservation of their cultural and religious identity with the language of instruction in schools and therefore preferred the Uyghur language school. However, from the mid-1980s onward, the Chinese government began to reduce teaching in Uyghur and starting mid-1990s also began to merge some schools from the two systems. By 2002, Xinjiang University, originally a bilingual institution, had ceased offering courses in the Uyghur language. From 2004 onward, the government policy has been that classes should be conducted in Chinese as much as possible and in some selected regions, instruction in Chinese began in the first grade. A special senior-secondary boarding school program for Uyghurs, the Xinjiang Class, with course work conducted entirely in Chinese was also established in 2000. Many schools have also moved toward using mainly Chinese in the 2010s, with teaching in the Uyghur language limited to only a few hours a week. The level of educational attainment among Uyghurs is generally lower than that of the Han Chinese; this may be due to the cost of education, the lack of proficiency in the Chinese language (now the main medium of instruction) among many Uyghurs, and poorer employment prospects for Uyghur graduates due to job discrimination in favor of Han Chinese. Uyghurs in China, unlike the Hui and Salar who are also mostly Muslim, generally do not oppose coeducation, however girls may be withdrawn from school earlier than boys. Traditional medicine Uyghur traditional medicine is known as Unani (طب یونانی), as historically used in the Mughal Empire. Sir Percy Sykes described the medicine as "based on the ancient Greek theory" and mentioned how ailments and sicknesses were treated in Through Deserts and Oases of Central Asia. Today, traditional medicine can still be found at street stands. Similar to other traditional