For giggles, I took a look at current FIFA ranking and the qualification process for the World Cup 2014. Here's a table shoiwng the number of participants and average FIFA ranking and the number of participants in the six federations.
Code:
5 36.6 52 Africa
4 52.3 43 Asia
13 11.2 53 Europe
4 23.5 35 CONCACAF (New Zealand (#97) played against Mexico in the play-in)
6 10.5 10 CONMEBOL (Uruguay played against Jordan in the play-in)
0 97.0 8 OCF (New Zealand (#97) played against Mexico in the play-in)
Note: OCF plays a home-away play-in against CONCACAF for the last of four qualifiers amongst the two federations and CONMEBOL plays a home-away play-in against Asia for the last of the ten qualifiers between the two federations.