How we use Census data

Most of our figures on the UK population come from Census data. This includes population statistics for England and Wales, and age and gender data for different ethnic groups.

We also use Census data to:

• work out rates on some of our data pages – for example, our stop and search data shows the stop and search rate per 1,000 people for every ethnic group
• act as a comparator – for example, our NHS workforce data compares the ethnic groups that make up the NHS workforce with the overall working age population

Problems using Census data

Using Census data can be problematic because:

• ethnicity categories are usually updated every Census, so datasets that use the 2001 Census ethnic categories have to be altered so they match more recent categories
• population figures for each area only include permanent residents and not visitors

Example:

In our data on the school teacher workforce, the ethnic groups follow the 2001 Census classification. However, the 2011 Census moved 'Chinese' from the ‘Any Other’ ethnic group to ‘Asian/Asian British’. This means that figures using 2011 Census categories can’t be compared with any using 2001 Census categories for 'Any Other' and 'Asian’.