The source should include a link to at least the 2021 census.
This is the link: https://www.ons.gov.uk/peoplepopulationandcommunity/culturalidentity/ethnicity/bulletins/ethnicgroupenglandandwales/census2021
Just search the page for "london".
Regions of England London remains the most ethnically diverse region of England and saw an 8.1 percentage point decrease of people who identified as "White: English, Welsh, Scottish, Northern Irish or British" (36.8%, 3.2 million in 2021, down from 44.9%, 3.7 million in 2011). In other regions, the percentages identifying their ethnic group this way ranged between 71.8% (4.3 million) in the West Midlands to 90.6% (2.4 million) in the North East.
(post is archived)