The National Statistics Socio-economic Classification is the official socio-economic classification in the United Kingdom. It is an adaptation of the Goldthorpe schema which was first known as the Nuffield Class Schema developed in the 1970s. It was developed using the Standard Occupational Classification 1990 (SOC90) and rebased on the Standard Occupational Classification 2000 (SOC2000) before its first major use on the 2001 UK census. The NS-SEC replaced two previous social classifications: Socio-economic Groups (SEG) and Social Class based on Occupation. The NS-SEC was rebased on the Standard Occupational Classification 2010 prior to the 2011 UK census and it will be further rebased on the new Standard Occupational Classification 2020 for use on the 2021 UK census.