The Socially Disadvantaged Groups include the Scheduled Castes (SCs), the Scheduled Tribes (STs), the Other Backward Classes (OBCs) and the Minorities. According to the 1991 Census, SCs account for 138.23 million (16.5 percent); STs 67.76 million (8.1 percent); and Minorities 145.31 million (17.2 percent). As regards OBCs, it is difficult to quantify the size of their population in the absence of the Census data. However, according to the estimates by the Mandal Commission in 1993, the OBCs constitute 52 per cent of the country’s total population. Some of them may belong to the categories of SCs and Minorities.