The UK censuses took place on 21st April 1991. They were run by the Census Office for Northern Ireland, General Register Office for Scotland, and the Office of Population and Surveys for both England and Wales. The UK comprises the countries of England, Wales, Scotland and Northern Ireland.Statistics from the UK censuses help paint a picture of the nation and how we live. They provide a detailed snapshot of the population and its characteristics, and underpin funding allocation to provide public services. The Northern Ireland Individual SAR is a 2% sample of individuals which was drawn from the full set of 1991 Census records. It was released to the then Census Microdata Unit (now the Centre for Census and Survey Research) in May 1994 who then undertook quality assurance work and produced documentation and additional derived variables. The dataset contains 31,967 person records and 53 variables. A number of protections are in place to ensure the anonymity of cases in the data including the low sampling fraction, grouping of some rare categories, limitation of geographical detail and record reordering so that the cases are not ordered geographically. Once the Household SAR (held under SN 7213) had been removed to avoid an overlap between the two files, remaining records were stratified into groups of 99 and two individuals were chosen from each group. Individuals in communal establishments were stratified geographically into groups of 50 people and one person was chosen at random from each group. Unlike Great Britain, 100% of Northern Ireland records were coded. For many variables, the codes that are used in the Northern Ireland SARs differ from those used in the GB SARs. Where this is the case, the Northern Ireland coding follows on numerically from the GB coding but it will not necessarily start at 1 and have a value for every succeeding integer. For example, 'household family type' uses quite different coding to the nearest GB equivalent 'family type': the GB codes run from 00 through to 08, whilst the Northern Ireland codes pick up from 09 and run through to 23. Further information, including guides and other documentation, may be found on the Cathie Marsh Centre for Survey Research Samples of Anonymised Records (SARS) website. Variables included in the 1991 Northern Ireland Individual SAR include: age, sex, marital status, employment status, religion, occupation, industry, social class, accommodation, bath/shower and indoor toilet facilities, tenure, economic position and social class of family head; and some limited information on other members of household, e.g. number of persons with long-term illness, number of pensioners and number of earners.