People have found that there 11.2 concussions every 10,000 games and practices. There are 6.3 concussions in college practices and games. In the NFL there was once 5.2 concussions per week. There are a bunch of adults and kids that get concussions every year.
There are many NFL players that are retired that have many issues from getting concussions. One example is Jonson #42. He retired because he had headaches instantly when he played in the NFL. There was Luke Keuchly has missed 3 games because of a concussion he says he has been having problems.