This can be calculated for 1951 and 1961, and then in 2001 and 2011, but the measures are actually rather different in the two pairs of years. For 1951 and 1961, the figures are for the proportion of people leaving school at or before age 15, i.e. before the ages at which public exams are usually first taken, while for 2001 and 2011 they are simply for people without any qualifications. Here it is particularly important to remember that, as the figures cover the whole working population, the data do not tell us what was currently happening in schools in the census year.

The very high national rates in 1951, 86% of the workforce of England and Wales lacking qualifications other than those acquired on the job, reflect the low priority given to the education of most of the population in the first half of the century, but this was already changing.