This chart created by humor website 9gag is based on the average penis sizes around the world, and everyone’s probably pretty jealous of Congo right now.
The original page doesn’t say where the statistics come from, but they definitely support some socially-perpetuated stereotypes.
The US is below the global average and if it’s assumed the rest of Western Europe hovers around the same range as Germany, I guess we can’t be surprised too when our girlfriends tell us they’re studying abroad for six extra semesters.
I gather these measurements are taken while the penis is in a state of erection. If so then I am above average at 9 1/2″