The last summer Olympics was in 2012. This quiz was made in 2014. After the 2016 Olympics in Rio, I'll update it.
What that means for the quiz is that there aren't really any fascinating omissions anymore. I liked the fact that before you could type in teams that are famous for being very good at football (Brazil, Germany) and not see them show up. I imagine quite a few were stunned by this. After these last Olympics, pretty much every team you would expect to have won gold has, except maybe Portugal. Or Colombia perhaps. Not interesting.