This might be useful
Turnout at the 2024 general election was 59.7%, which was the lowest at a general election since 2001. Turnout was 7.6 percentage points lower than in 2019.This represented the largest drop in turnout between elections since between 1997 and 2001.
The chart below shows turnout at general elections since 1918, during which time it has varied between 57.2% (1918) and 83.5% (1950). Since the drop in 2001, turnout has never fully returned to the levels between the 1922 and 1997.
https://commonslibrary.parliament.uk...-2024-turnout/