 Rudolph noted that, although "necessarily tentative" because of being based on figures from the 1931 census, the Vanniyars in the 1980s constituted around 10 per cent of the population of Tamil Nadu, being particularly prevalent in the northernmost districts of Chingelput, North Arcot, South Arcot and Salem, where they formed around 25 per cent of the population.Traditionally, most Vanniyars are agricultural labourers but they are increasingly benefiting from political influence and organisation and they now own 50 per cent of the lands of the traditional landowners.The Vanniyars who previously were of the Backward Class category, were now designated as a Most Backward Caste after successful agitations by them in the 1980s.