First, let me thank all of you for your responses.
I suppose I'm interested in the insurance data because it gives an overall, AVERAGE measure of risk for a particular activity or a particular factor. Sometimes that average can be instructive. A couple of years ago I looked up a quote for life insurance. At the time I was 205 pounds (5'10 1/2"). I found that this weight put me in the increased rate category and that I had to be 195 pounds to get the normal rate. That was a bit of an eye-opener because while I knew I was a bit overweight I didn't think much of it. However, masses of statistics said otherwise.
Jared, your point is well taken about confounding factors and that ocean voyaging may not be statistically significant. If that is the case, then that would be interesting to know.
Of course, if we choose to engage in an activity, responsible, mature adults try to minimize their risks. If I scuba dive, I try to minimize the risks, but I still know that is significantly riskier than not getting in the water. Fine. I'll take the risks because I want the benefits of the activity.
Kimberlite, thanks for mentioning the other exclusions from yacht insurance. I knew about hurricane areas but not about the high latitudes. I expect that in the high latitudes a "hull loss" is most likely also a "crew loss".
Sailandor, thanks for mentioning Jimmy Cornell. I sent him an email yesterday at his noonsite.com website. I expect that if anyone has numerical data that he does. I'll let everyone know if I find out anything.