I find this a fascinating topic - risk assessment is a complex and very interesting topic, both from a psychological and from a quantitative perspective. We tend not to to do it very well, unless we have rigorous metrics, and as others have pointed out, the relevant statistics are as often abused as properly used. The edarnell.com page that Buck cited looks like a very nice attempt to break down the frequencies of fatal back-country events. IMO, it provides a pretty clear picture of the things one has to avoid to stay safe. The main thing I'm wondering after reading this summary is what proportion of the people were day-hikers and what proportion were multi-day backpackers. It has seemed to me for several years that most of the fatalities I hear about are among day-hikers, and it kind of makes sense. If I get lost backpacking, the biggest risk is that I'll worry someone by not getting out when planned. If a dayhiker gets lost and doesn't know how to create shelter, it can easily be fatal. I may also be wrong, but it's also my impression that it's usually dayhikers who have most of the worst falls (maybe it's just because there are more of them, or maybe the reporting's clearer).
It can often be pretty trick to compare hiking risks to other risks, especially when there aren't clear data on the frequencies of events. I've often said that the drive to the trailhead is the most dangerous part, but is it really? It probably depends on where I'm backpacking. If I drive 1000 miles roundtrip, then my chance of dying from the trip is on the order of 1/100,000. I have no idea what most of the annual risks mean in the besthealthdegrees chart (were those people out for 5 days/year or 100?), but if the McKinley mountaineering data are to be believed, then a 10 day trip there gives me about 1/1000 risk (~ 100 times more than a 1000 mile drive). On well-traveled, gentle sections of the AT, my chances of dying from an accident are probably lower than they are on a typical non-hiking day. If I'm solo in some rugged true wilderness, it might be closer to the McKinley stats.
What seems most clear to me personally, though, is that the biggest risk associated with backpacking is not doing it. Other than motor vehicle-related risks, falls, and poisoning (the big three accidental causes), almost all of the biggest risks are non-communicable disease risks that are reduced by getting out and getting moving.