> And to flip the presentation of your stat around, that means 40% of motorbike riders have been in an accident. That sounds really high to me given the potential consequences!

It sounds scary because it involves every type of accident, even minor ones. Useful to think about how many cars have ever been in accidents too, which should be around the same. The problem with motorcycle accidents is the fatality rates, just as you say, not the percentage of minor+major accidents.