David, I've been making assumptions about your motivation for this survey, too, and your second post seems to indicate I've been assuming along the right track.... After "discovering" that people seem to be using knives for defense less than 0.5% of the times they use knives, you conclude, "Therefore it matters very little what style of knife or design you carry."
Well, maybe you're right ... maybe it doesn't matter what kind of insurance I carry on my car or how strong my seat belt is ... let's start using seat belts made out of any convenient fabric we might happen to like the looks of or can get cheap; it doesn't matter what.... After all, my seat belts have saved my life less than 0.5% of the times I've buckled them, so what difference does it make how well they're designed for a purpose they're used for less than 0.5% of the times they're used?
All styles and designs of knives are not equally good for defensive purposes. Of course any knife is better than nothing, but strange as it may seem, that doesn't mean they're all equally good.
There is little if any correlation between looking scary to the uninitiated and effectiveness. In fact there can be a reverse correlation; many of the features that look scary to the uninitiated make a knife less effective for defense, such as brass-knuckle handles, serrations, American tanto blade design, thin narrow points, large conspicuous guards, excessively long blades, etc. Some people even seem to think slots and holes in the blade make a knife look scary.
It seems to me asking what percentage of knife use is defensive was rather transparent ... reminiscent of the carefully worded questions toothpaste companies survey dentists with. Another percentage question that might be more interesting would be, "What percentage of the things you have cut in your lifetime so far would you have been alive to cut if you had never been prepared to defend yourself with a knife?"
-Cougar Allen :{)