Re: European maps on social issues
It's very difficult to determine really. But if they go by what people are practicing then it would invlove how many clubs there are registered, how many people take part of clubs activity etc.
Another option would be to look at how many people take part of the competitions (amateur or professional), but I suspect it's not the case, otherwise running/jogging would top football, no?
And then the TV ratings plus ticket sales. But this one is a slippery road because if they don't show gymnastics on TV how would it get a rating. And if one sports event is on a big arena while the other one isn't, is it fair to compare the ticket sales..