I compared top 10 UK and Japan games for 2007. However Japanese list include 9 milion seller while UK has only 2 the sum of units sold is higher for Japan only by around 50%. Excally it's 12.49 milion units for Japanese top 10 vs 8.22 mln for UK top 10. So in value UK is very close to Japan but in units it's still significantly lower.
UK top 10 for 2007:
http://vgchartz.com/forum/thread.php?id=13932
Japanese top 50 for 2007:
http://vgchartz.com/forum/thread.php?id=23671
This year is already shaping better for Japan. MHP2G with 1.66 mln is already close to last year number 1 Wii Sports (1.94 mln) and SSMB with 1.65 mln is higher than last year runner-up (Wii Play 1.53 mln).







