The purpose of the project was to provide machine-readable economic and social history statistics relating to the whole of Ireland for the period 1821-1971. Further information about the project is available on the QUB Centre for Data Digitisation and Analysis website. The main tables are: Total number of unmarried, married and widowed people grouped by counties, age groups and gender. Total number of unmarried, married and widowed people grouped by poor law unions, age groups and gender (1871-1911). Please note: this study does not include information on named individuals and would therefore not be useful for personal family history research.