New questions were introduced, or questions altered from previous years, to reflect the changing users requirements, social conditions , and experience with previous censuses and test censuses.
For example, the question on limiting long-term illness was introduced to provide more useful information about the impact of chronic illness on quality of life. (see Gould and Jones, 1996). On ethnicity, previous censuses had failed to provide a true reflection of the ethnic minority population in the UK so this question was introduced in 1991, allowing respondents to state the ethnic group to which they belonged.
Six new questions were introduced in 1991 and a more detailed explanation of the reason for their inclusion can be found in The UK Census of Population 1991, Martin, 1993.