With the exception of 2001, these data have been created for Vision of Britain by re-districting statistics originally reported for other units. We have also had to deal with variations in the categories and classifications used in statistical reporting over the years.

• 1851: The data on births and on infant deaths come from the Registration District-level data within the Registration sub-District statistics in the Registrar General's Annual Report for 1851. Fertility rate calculations also use data on Registration District age structure from the 1851 Census of Population. Scottish data are not currently included.
• 1881: The data on births and on infant deaths come from the sub-District-level table published regularly in the Registrar General's Quarterly Returns, summing over the four quarters of 1881. Fertility rate calculations also use data on Registration District age structure from the 1881 Census of Population. Scottish data are not currently included.
• 1911: The data on births and on infant deaths come from the Local Government District-level table published in the Registrar General's Annual Report for 1911. Fertility rate calculations also use data on Registration District age structure from the 1911 Census of Population. Scottish data are not currently included.
• 1921-1951: The data on births and on infant deaths in England and Wales come from the table covering all individual Local Government Districts published in the Registrar General's Statistical Review, Part I, Medical for each year. The Scottish were computed from the tables giving 'Statistics of Public Health Districts' in the Annual Reports of the Registrar-General for Scotland, but using data only for county totals, the four cities of Aberdeen, Dundee, Edinburgh and Glasgow, and selected major burghs: Airdrie, Arbroath, Ayr, Clydebank, Coatbridge, Dumbarton, Dumfries, Dunfermline, Falkirk, Greenock, Hamilton, Inverness, Kilmarnock, Kirkcaldy, Motherwell and Wishaw, Paisley, Perth, Port Glasgow, Rutherglen and Stirling. Fertility rate calculations also use data on local government district age structure from the relevant Censuses of Population.
• 1981-1991: The Linking Censuses through Time web site developed by Danny Dorling of Sheffield University does not cover vital registration data. Instead, Danny Dorling supplied us directly with statistics for the whole of Great Britain, redistricted by him using similar techniques to those used in LCT. The 'births' data are in fact census counts of children under 1, interpolated between census years and then scaled so that the national total of babies for census years matches the national birth counts. Fertility rate calculations also use district-level age structure data from the relevant censuses, redistricted using LCT.
• 2001: The data are as originally reported for current districts by the Office for National Statistics and the General Register Office (Scotland). They were supplied for the Vision of Britain site by Peter Congdon of Queen Mary, University of London.