Other things to consider when looking at fatality rates: with motorcycles (at least in FL; as for other states I dont know) you are not legally bound to wear a helmet if you're 18+ and have insurance (same with cyclists). I do know that last year's biketoberfest and bikeweek, they saw a dramatic increase in motorcycle fatalities. See a connection here anyone?
Also, based on what Geonz said, autos have gotten quite large. SUV's are huge and from what I see, a lot of women drive these monsters because they feel more protected and safe. Hint: just because its big, doesnt mean your safe. When they're backing out of their driveway and nearly run my a$$ over, its my fault because they couldn't see me. I would think because of the size of these things, the chances of a driver hitting someone would be higher because of the blindspots and the maneuverablity.