Besides the Tai-speaking minorities, there were a number of peoples speaking languages of other families (although increasing numbers were acquainted with a Thai dialect, especially Central Thai, if they acquired the language in school). Some--such as the Khmer in the eastern portion of the country, the Karen in the northern and western parts of Thailand, and the Malay in the South--found themselves within the boundaries of Thailand as a consequence of conflict and shifting borders. Others, such as many of the hill peoples, were relatively recent migrants from China and the Indochinese Peninsula. They found their way to the peripheries of Thailand either in search of land or to escape political turmoil. Groups entering Thailand that had been minorities in their countries of origin, as hill peoples typically were, became more or less permanent residents of Thailand, although still largely unassimilated. Others, particularly the Mon, who lived in the central region, became substantially integrated. The groups of Vietnamese who had arrived for various reasons from the nineteenth through the mid-twentieth centuries varied in the extent to which they were rooted in Thailand. Some groups of Khmer, refugees from political turmoil in their own country since 1975, were also recent arrivals in Thailand. Finally, there were the Chinese. Of the estimated 6 million in Thailand in 1987, most could be differentiated by the region of China from which they came, when they had arrived, and the extent to which they had been assimilated into Thai society.