Findmypast adds England & Wales, Electoral Registers 1920

Findmypast promotes the 6,775,052 entries in the new England & Wales, Electoral Registers database as a 1920 census substitute. These indexed records, which can be searched by name, year, constituency, polling district and keyword, contain voting age men and women. 
While the population in 1920 was over 37 million many were underage or otherwise ineligible to vote.
The geographical coverage is incomplete. Included are records from 27 of the more populous counties: Berkshire, Cambridgeshire, Cheshire, Cumberland, Derbyshire, Devon, Dorset, Durham, Essex, Glamorganshire, Gloucestershire, Hampshire, Herefordshire, Hertfordshire, Kent, Lancashire, Leicestershire, Lincolnshire, London, Middlesex, Norfolk, Northamptonshire, Northumberland,
Nottinghamshire, Somerset, Sussex, Yorkshire.
Missing are Bedfordshire, Buckinghamshire, Cornwall, Huntingdonshire, Monmouthshire, Oxfordshire, Rutland, Shropshire, Staffordshire, Suffolk, Surrey, Warwickshire, Westmorland, Wiltshire, Worcestershire, and all Welsh counties except Glamorganshire.
Also the database includes more than one enumeration for the year, spring and autumn, so the vast majority of people in samples I explored are included twice.
Overall there's perhaps a one in ten chance of finding a person who was living in England and Wales in 1920.