2012 Atendees list ( http://fronteers.nl/congres/2012/attendees ) has no stats on how many atendees there are from each country. Wanting to visualize them, I've scraped the website with Yahoo's YQL parsed the data and created a pie with Raphael
You can now easily see that over 50% are still Dutch http://andreieftimie.github.com/fronteers/
I am aiming to take some historical data and put this into perspective. Expect more stats :)