Report provides population numbers for mountain peoples ("hill tribes") and ethnic communities in the northeast and is explicit about its reliance on the Mahidol University Ethnolinguistic Maps of Thailand data. Thus, though over 3.288 million people in the northeast alone could not be categorised, the population and percentages of other ethnic communities c. 1997 are known and constitute minimum populations. In descending order, the largest (equal to or greater than 400,000) are: 15,080,000 Lao (24.9 percent) consisting of the Thai Lao (14 million) and other smaller Lao-related groups, namely the Thai Loei (400-500,000), Lao Lom (350,000), Lao Wiang/Klang (200,000), Lao Khrang (90,000), Lao Ngaew (30,000), and Lao Ti (10,000) six million Khon Muang (9.9 percent, also called Northern Thais) 4.5 million Pak Tai (7.5 percent, also called Southern Thais) 1.4 million Khmer Leu (2.3 percent, also called Northern Khmer) 900,000 Malay (1.5 percent) 500,000 Nyaw (0.8 percent) 470,000 Phu Thai (0.8 percent) 400,000 Kuy/Kuay (also Suay) (0.7 percent) 350,000 Karen (0.6 percent). Khmer and Mon-Khmer make up approximately 6 percent, the Malays of southern Thailand make up around 3 percent. Among the groups categorized as hill tribes in the northern provinces, Hmong (Mien), Karen, and other small hill tribes make up over 1 percent. In official Thai documents, the term "hill tribe" (chao khao) began to appear in the 1960s. This term highlights a "hill and valley" dichotomy that is based on an ancient social relationship existing in most of northern and western Thailand, as well as in Sipsongpanna and northern Vietnam. For the most part the Dai/Tai/Thai occupied the more fertile intermontane basins and valleys, while the less powerful groups lived at the less rich higher elevations. This dichotomy was often accompanied by a master/serf relationship. Vestiges of this dichotomy remain today: for example, 30 percent of ethnic minority children in Thailand cannot read by second grade. The corresponding figure for Bangkok is one percent. List (by population size) Tais – c. 53–56.5 million Central Thai (Siamese) – c. 25 million Isan (Thai-Lao; Thai Isan; Isan Lao) – c. 18.5–20 million Yuan (Thai Yuan; Lanna) – c. 6–7 million Southern Thai (Thai Pak Tai, Southern Siamese) – c. 5.5 million Chinese (primarily Teochew ) – c. 6–9 million assimilated Sino-Thai (Luk Chin) – > 4.5 million non-assimilated Chinese – c. 1.4 million Malays – 2–4 million Khmer – > 1.2 million Karen – c. 1 million Phu Thai –