More than 5.5 million Brits are living abroad, with more soon to be joining them:
“some 2,000 British citizens moved permanently away from the UK every week in 2005.”
Thats a lot of people moving out.
But, hang on a minute; look at the map in the article; the UK is grey. Checking the legend, grey is “No Information”.
The BBC should really google for “census uk” :)