This is a huge resource for British genealogists. Kudos to the British Library for their foresight in initiating the project, as well as conserving the newspapers over decades and centuries, and to their operational partner Findmypast.
Best coverage is for London-based newspapers, as would be expected.
Weighted by population the five English counties with top coverage are: Bristol, followed by Gloucestershire, Devon, East Riding of Yorkshire, Tyne and Wear. The five least well served on a population weighted basis, less than one tenth that of the top, are: Essex, Norfolk, Dorset, Surrey and with the poorest coverage, Hertfordshire.
Wales is less well covered, understandably given the 1.1 million page free digitized newspaper resource provided by the National Library of Wales.
Scotland, headquarters of the company is the best served of the counties per capita. Population data are not available on the same basis as the newspaper county categories although Angus with nearly eight times the coverage per capita of any English county appears best served. Midlothian, Aberdeenshire and Stirlingshire are not far behind.
For Northern Ireland Antrim, Fermanagh and Londonderry and for the Republic Waterford, Dublin, Tipperary and Wexford have best per capita coverage equivalent to the best English counties.