CPR Training

My son recently completed CPR training in his health class. He received a card saying that he is now certified in CPR administration. I have done this before, especially when I was working as a teacher "back in the day." I think you have to renew every few years to keep it current--mine has elapsed. I think I would remember everything, though. I wonder how often people end up using this certification? I mean, everyday people who do not work in the medical world at all? Whenever you hear of something happening to someone, usually 911 gets called and the 911 operator talks someone through it. I am curious how often lives are saved due to these quick courses and certification classes? I think it is good--I am glad that my son might could help someone in a crisis with CPR. I just don't know if people are using it as much as intended or not. I did hear about a boy saving a classmate from choking by using the Heimlich maneuver(sp?)--that may be an even more important thing for people to know. I think I learned both in my classes--I will ask my son if he did as well. He is learning a lot this year! :)