Just to be very picky the statistics given were for England and Wales not the entire UK

England : 49,181,000 (2001)
Wales: 2,903,000 (2001)

= 52,084,000

This would alter the stats a bit as you're out by almost 8 million people.

Scotland : 5,064,000 (2001)
Northern Ireland: 1,689,000 (2001)

There may be some slight shifts in those by 2004 but they shouldn't be too far off.