Checkout the bar for "Europe". My take on this is that this is the entire Eurozone - 17 nations. In which case, you need to get the bar and make it 1/17th as big, and this will tell you the average for each nation state in the Eurozone.
All seventeen nation states in the zone, combined, add up to about the same level of debt as, say, Norway or Sweden (two of the great poster-children of prudence) on their own.
And yet, the Eurozone is in a debt crisis? Interesting, no?
Let's not dwell too long on the size of that UK bar on the left... :-{