The Bolsheviks also wanted to get more support from ethnic minority groups within the Soviet Union, many of whom were previously oppressed under Tsarist rule. The Soviet Union continued to ask about ethnicity for the rest of its existence, and Russia also asked about ethnicity in its two post-Soviet censuses of 2002 and 2010. Unlike in 1989, the 2002 census did not require respondents to prove their ethnicity/nationality when they responded to this question. The number of ethnicity/nationality options available on Soviet censuses was enormous—the Soviet Union offered 194 different choices for ethnicity/nationality in its 1926 census. There were 97 options in 1939, 126 options in 1959, 122 options in 1970, 123 options in 1979, and 128 options for the Soviet Union in 1989. There were 192 ethnicity/nationality options for Russia in 2002. The people in Singapore were numerated by ethnicity from at least 1947 up to the most recent Singaporean census in 2010. Sri Lanka enumerated its population by ethnicity in 1971, 1981, and 2012. People in Tajikistan (when it was still a part of the Russian Empire) were enumerated by native tongue in the 1897 Russian Empire Census. In addition to the Soviet Union enumerating people by ethnicity for its entire existence, Tajikistan also enumerated people by ethnicity in its post-Soviet censuses in 2000 and 2010. Thailand enumerated people by ethnicity in 1947. Between 1881 and 1893 the Ottoman Empire implemented its first census, which enumerated the people in the empire by ethnicity. Some other censuses and studies were conducted in the Ottoman Empire for enumerating the population by ethnicity after the first Ottoman census. People in Turkmenistan (when it was still a part of the Russian Empire) were enumerated by native tongue in the 1897 Russian Empire Census. In addition to the Soviet Union enumerating people by ethnicity for its entire existence, Turkmenistan also enumerated people by ethnicity in its only post-Soviet census in 1995. People in Uzbekistan (when it was still a part of the Russian Empire) were enumerated by native tongue in the 1897 Russian Empire Census. The Soviet Union (to which Uzbekistan also belonged) enumerated people by ethnicity for its entire existence. Uzbekistan has not conducted any censuses at all since 1989. Communist North Vietnam enumerated people by ethnicity in 1960, when Vietnam was still divided into two countries. After Vietnamese reunification, Vietnam enumerated its population by ethnicity from 1979 up to the most recent census in 2019. Yemen enumerated its population by ethnicity in 1994.