This is the National Identity data (KS202) from the 2011 Census. The data provides how usual residents described their nationality identity.
Data is for England, South East Midlands Districts and Wards and Milton Keynes LSOA and OA.
The question was:
How would you describe your national identity? (tick all that apply)
The 2011 census in England and Wales took place on 27th March 2011. It provides a snapshot of the population and its characteristics on that day.
Further information about the census estimates, including details about the methodology is available here: http://www.ons.gov.uk/ons/guide-method/census/2011/index.html