A Census or population count has taken place once a decade in England and Wales since 1801 (except 1941) and is the only time every person and household is counted right across the UK. The Office for National Statistics (ONS) is responsible for the census in England and Wales, and carried out the most recent in March 2011. The Census remains the largest single source of social statistics in England and Wales. Please click on the individual topic areas for further information.