According to the CIA World Factbook, citing a 1987 Iraqi government estimate, the population of Iraq is 75–80% Arab followed by 15% Kurds. In addition, the estimate claims that other minorities form 5% of the country's population, including the Turkmen/Turcoman, Assyrians, Yezidis, Shabak, Kaka'i, Bedouins, Roma, Circassians, Sabaean-Mandaean, and Persians. However, the International Crisis Group points out that figures from the 1987 census, as well as the 1967, 1977, and 1997 censuses, "are all considered highly problematic, due to suspicions of regime manipulation" because Iraqi citizens were only allowed to indicate belonging to either the Arab or Kurdish ethnic groups; consequently, this skewed the number of other ethnic minorities, such as Iraq's third largest ethnic group – the Turkmens.