If you look at statistics for bystanders killed at UK airshows, then the figures are even starker: 29 in 1952 (the Farnborough DH.110 crash) then zero every year since until now.
However, statistical comparisons are not the end of the matter, as an important factor is how such risks are perceived.
I'll note now that I'm not a pilot (and my flying experience is limited to 25 hours on Bulldogs a quarter of a century ago, and two trips in a JP5 at Cranditz not much later.) But I was an RAF engineering officer, and I'm now a barrister. In both jobs I've had to deal with risk assessment, and as a lawyer I have to look at the questions of how extensive a duty of care to others is in particular circumstances and what constitutes a breach of that duty.
I think it's fair to say that people as a whole are more willing to accept risk if they have some control, or even some perceived level of control, over it. Driving is one of the more dangerous activities most people do, but by and large we accept the risk because of (a) the benefit to ourselves and (b) the feeling that it's a risk we in part control. I'd suggest that's why public transport accidents attract far more publicity than the general run of road accidents; when we get on a train, we are accepting a risk that is entirely controlled by someone else.
In short, there is a hierarchy of risk acceptance:
1) Risks we take because we get a benefit from them, and which we believe are at least partly under our control (e.g. driving, sports.)
2) Risks we take because we get a benefit from them, but where the risk factors are under the control of others (e.g. public transport, surgical procedures.)
3) Risks we do not chose to take and which are not under our control.
The third category particularly vexes people because we can't avoid them and we have no control over them. As such they concern people out of proportion to the actual risk involved. Examples include terrorism, nuclear accidents and the like.
Returning to the matter at hand, if you are displaying an aircraft you are in risk category 1. If you are a spectator at an airshow you are in risk category 2. The people who died yesterday were, I'd argue, mainly in risk category 3. (It is not yet clear if all were road-users or if any were people watching the flying - there is certainly a clump of the latter visible in some of the pictures, and it must have been one of them who took the close-up that's on the front page of half the papers this morning.) I therefore expect that there will be a lot of public concern, or at least concern expressed on behalf of the public (not always the same thing) about how this incident killed people who hadn't even accepted the risk of spectating. That's why it will attract attention out of proportion to the objective fatality risk.