Well, it may be related to things like.... Again, I'm not a medical doctor, but we do have Dr. Robin Poole, who is an expert on these things, on our council, and he probably would have better theories than me.
I imagine that if you're trudging through Normandy, or maybe worse, trudging through the mountains of Sicily and Italy, as the Canadian army did, that could be a pretty rough life. I could see that resulting in minor stress fractures, and so forth, that you would live with for a while and that you may not even notice until later in life. I think that could be a big cause of it.
Again, you couldn't track that back; it really hits the crisis point when someone is say 83 years old. I think it would be ridiculous to try to track that back and say, “Well, I was riding in this tank in Italy and it was a bumpy road”. I don't think you can track it back; but that's my guess about the kinds of connections that would account for that.
That's in the chart on page 13, by the way—figure 5 on page 13.