Where did you get this 50% number or is it entirely made up? Would be nice to have a reference or a source when you make such claims. I don't believe that figure is true, it will be high but I likely to be that high.
According to what I have seen online before, the percentage of gamblers in the world is around 25% which is half of what the OP posted and not 50%. Nearly all children will not be there while women that like gambling are not really many compared to men. Also many countries like the Muslim countries forbids gambling which will make most of people in such countries not to be gambling.