But my thinking is, let say 100 people visit the emergency. OK it works out to 1% of the people we know about, but what if 1,000 people actually hit their heads but the helmet did it's job for 900 people out of the 1,000 that bounced their head on the pavement but they didn't go to the emergency... Kind of skews the numbers if you don't include those 900 people... No?