This machine-readable version of John Williams' <i>Digest of Welsh Historical Statistics</i> is the result of a collaboration between the Statistical Directorate of the National Assembly for Wales, the History Data Service and the Centre for Data Digitisation and Analysis at Queen's University Belfast. John Williams' <i>Digest of Welsh Historical Statistics</i> is intended to provide a service for those working on the history of modern Wales. It arises from a belief that the quantitative element is a necessary and important part of the historical record; from an awareness that it was an aspect that was particularly inaccessible for scholars of Welsh history; and from a conviction that some encouragement in the use of quantitative material was necessary. It is modelled on the two volumes dedicated to British historical statistics: Mitchell, B.R. and Deane, P. (1962) <i>Abstract of British historical statistics</i> and Mitchell, B.R. and Jones, H.G. (1971) <i>Second abstract of British historical statistics</i>. Occupations, 1801-1971. Occupations by sex, by county, 1801-1971. Employment. Estimated number of insured employees (employed and unemployed), by sex and industry, 1939-1974. Number and percentage of unemployed, by sex, 1923-1975. Unemployment: vacancies unfilled, by sex, 1949-1974. Unemployment by age groups, duration and sex, 1935-1940, 1946-1976. Number of persons placed in employment by employment exchanges and youth employment services, 1948-1974. Number of Trades Councils and number of Trade Union members represented, 1894-1924. Total number of workpeople affected by, and days lost through, industrial disputes, 1891-1913. Industrial disputes by industry, 1897-1974. Please note: this study does not include information on named individuals and would therefore not be useful for personal family history research.