Well, for one thing I bet that if kids age 4 to 16, who are now on bikes, all drove cars the numbers would be quite different.

So, in all seriousness, let's compare Brussels sprouts to other Brussels sprouts: since only 16 y/o + drive a car, only 16 y/o cyclists should be taken into account.

I also agree that time spent in the saddle is more meaningful than distance. If we stuck to distance alone, going on foot would seem to be a suicidal endeavor.

Oh and truisms are good arguments sometimes like the fact that if there weren't any cars there would a whole lot less "bicycle injuries" while, if there weren't any bicycles it would still be dangerous to drive a car.