These notes concern the historical statistics for modern local authorities, which 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.

• 1951: The data for England and Wales come from tables 25, 'Occupied Population in 3 age sections by 5 terminal ages', for 'Administrative County, County Boroughs, Urban Areas with 50,000 Population or more and Urban Remainder', and 26, 'Occupied Male Population by 5 terminal ages', for 'Urban Areas of Less than 50,000 and Rural Districts'. They cover the age at which people finished their education, rather than any particular qualifications they obtained, so we assume that those who finished their schooling before age 15 were unqualified, and those who stayed on past 20 had degrees or equivalent. National totals for England and Wales have been added from Table 44, "Occupied population in 9 Age Sections each classified by 5 TERMINAL EDUCATION AGES", on p.160 of the 1951 General Tables report. All data for Scotland come from table 17, "Occupied Population classified according to 11 terminal educational ages, (a) Scotland by 9 age sections and (b) Administrative, etc. Areas by All Ages" for "(a) Nation and (b) Divisions, Cities, Counties and Large Burghs" in the Occupations and Industries volume of the 1951 census reports. Data for Small Burghs and Districts of County have been estimated by allocating county residuals in proportion to total population aged 15 and over. There are no data on voluntary schooling.
• 1961: Data for England and Wales are from table 4, "Population aged 25 and over by 7 Terminal Age groups" for "Counties, Local Authority Areas, Conurbation Centres, New Towns (10 per cent sample)" (pp.67-111) in the Education Tables volume of the 1961 census reports. National totals for England and Wales are from Table 1, "Population 15 and over in 9 age sections classified by 16 Terminal Education Age groups", on page 1 of the same report. This goes into more detail, so terminal age groups were merged to match those used in table 4, and numbers aged 15-19 and 20-24 were deducted from the totals aged 15 and over to compute numbers aged 25 and over. Data for Scotland are from table 4, "Population aged 25 and over by 7 Terminal Age groups" for "Cities, Counties, New Towns (10 per cent sample)" (pp.22-23) in the Terminal Education Age leaflet. As the Scottish data provide only City and County totals, numbers in each Burgh and District of County have been estimated by allocating county totals in proportion to their share of the male or female population aged 25 and over. All data have been multipled by ten to adjust for sampling. National totals for Scotland are from Table 1, "Population 15 and over in 9 age sections classified by 16 Terminal Education Age groups", on page 2 of the same report. This goes into more detail, so terminal age groups were merged to match those used in table 4, and numbers aged 15-19 and 20-24 were deducted from the totals aged 15 and over to compute numbers aged 25 and over. Despite this complication, the computed sum of all_ages for all districts exactly match the reported Scotland figure for both men and women.
• 1971: The data are computed from table SAS23 in the 1971 Small Area Statistics, "SEG and economic position (10% Sample): Economically active residents". The original data are for enumeration districts, and were downloaded from the CASWEB system on 9th July 2016. These data are particularly limited, and the only measure which can be calculated is 'graduates', defined as those with degrees or Higher National Certificates, expressed as a percentage of all economically active or retired.
• 1991: The data are computed from Table S84, "Qualified manpower (10% sample): Residents aged 18 and over." from the 1991 Census of Population. The data were downloaded from the NOMIS online system on 10th June 2016.
• 2001: The data were calculated from Table CS032, "Sex, Age and Level of Qualifications by Economic Activity: All People Aged 16 to 74", in the Census Area Statistics dataset tables from the 2001 Census of Population. They were downloaded from the CASWEB system on 23rd February 2017, but the geographies used vary: England: CAS Wards; Wales: CAS Electoral Division; Scotland: ST (Standard Table) Postcode Sector.
• 2011: Data for England and Wales are taken directly from table KS501EW, "Qualifications and Students" for Local Authorities from the 2011 Census Key Statistics release. They were downloaded on 22nd October 2015 from the Neighbourhood Statistics web site. Scottish data similarly come from Table KS501SC, "Qualifications and Students", for local authorities. Thy data were downloaded on 17th November 2015 from the Standard Outputs section of the Scotland's Census website.