I think a lot more research needs to be done to really understand some of the risks in different sports at different ages. One thing we have seen in some of the hockey work our group has done over the last number of years is that we actually do see a spike in the risk of concussion in the 11- and 12-year-old age group. The rates of concussion would be very high, almost similar to what you'd see at a professional level, and then that rate comes back down again. Potentially, then, that's a vulnerable age for those kids.
Ultimately, we do see that decrease in risk in terms of absolutely not playing. I think that's an interesting question, but it would be interesting to look at some of the different rules around risk. I know that a lot of the sports are doing some evaluation to look at that—i.e., around tackling and limiting contact at practices. There is evaluation going on to look at some of those. It will be interesting to see what some of that research shows.