Well...I'd be willing to bet I hold a very weird record, though I never coached Sturgeon. I've coached two players (four years each) who had to wear helmets while playing in college, John Peckinpaugh (IPFW) and Kendall Griffin (Wright State). Both had concussions in high school. Both were physical players and suffered multiple concussions in college.
In Griffin's case, he suffered two concussions in high school. He played football and basketball at Avon. Both of his concussions were in basketball. The first one came during his sophomore year about a month in. The second one came the second day of practice.
Griffin is now an IP attorney, making good money. Peckingpaugh is the head coach at Kokomo HS.
Common? Not nearly as common as football and hockey, which are collision sports, but I think every week there is an NBA players who enters concussion protocol. In the NFL you might get one per team per week, if not slightly more.