The Yi or Nuosu people, Nuosu: , ; Hanzi transcription: ; historically known as the Lolo, ; ; are an ethnic group in China, Vietnam, Laos and Thailand. Numbering nine million people, they are the seventh largest of the 55 ethnic minority groups officially recognized by the People's Republic of China. They live primarily in rural areas of Sichuan, Yunnan, Guizhou, and Guangxi, usually in mountainous regions. The Liangshan Yi Autonomous Prefecture is home to the largest population of Yi people within mainland China, with two million Yi people in the region. For other countries, as of 1999, there were 3,300 Lô Lô people living in the Hà Giang, Cao Bằng, and Lào Cai provinces in Northern Vietnam. The Yi speak various Loloish languages, closely related to Burmese. The prestige variety is Nuosu, which is written in the Yi script. Location Of the more than 9 million Yi people, over 4.5 million live in Yunnan Province, 2.5 million live in southern Sichuan Province and 1 million live in the northwest corner of Guizhou Province. Nearly all the Yi live in mountainous areas, often carving out their existence on the sides of steep mountain slopes far from the cities of China. The altitudinal differences of the Yi areas directly affect the climate and precipitation of these areas. These striking differences are the basis of the old saying that "The weather is different a few miles away" in the Yi area. Yi populations in different areas are very different from one another, making their living in completely different ways. Subgroups Although different groups of Yi refer to themselves in different ways (including Nisu, Sani, Axi, Lolo, and Acheh) and sometimes speak mutually unintelligible languages, they have been grouped into a single ethnicity by the Chinese and the various local appellations can be classified into three groups: Ni (). The appellations of Nuosu, Nasu, Nesu, Nisu and other similar names are considered derivatives of the original autonym "" (Nip) appended with the suffix -su, indicating "people". The name "Sani" is also a variety of this group. Further, it is widely believed that the Chinese names 夷 and 彝 (both pinyin: Yí) were derived from Ni. Lolo. The appellations of Lolo, Lolopu, etc. are related to the Yi people's worship of the tiger, as "lo" in their dialects means "tiger". "Lo" is also the basis for the Chinese exonym Luóluó 猓猓, 倮倮 or 罗罗.