The EU accounts for 14% of global GDP, so accounting for 16% of top 100 in market cap isn't terrible (if we're weighing each in the top 100 equally).
It's not like those are independent variables though. The idea is that if Europe were more competitive and did a better job fostering innovation then both its percentage of global GDP and top companies by market cap would be higher.
and 5% of the population so still not too bad