R44/R22 are the only helicopters on that list with piston engines. Maybe it's a numbers thing but the turboshaft R66 isn't there.
I wonder what it would look like if they bucketed the crashes based on pilot flight time. R44 is REALLY popular with flight schools. Then again, that is probably because they are super inexpensive and may be less safe. Many flight schools are notorious for unsafe GA aircraft.
I wonder if low-end aircraft have more novice pilots. Also, more passengers may lead to more fatalities? (r22 vs r44)