Carstairs deprivation scores were originally created for Scottish postcode sectors in 1981 as a measure of material deprivation. The scores were constructed from four census variables: car ownership, male unemployment, overcrowding and low social class. Since then, scores have been updated every ten years. Although there have been changes in some of the census variable definitions over time, the variables used in subsequent years have been kept as similar as possible to those used in 1981.