Free: Contests & Raffles.
I am skeptical about that percentage. I know quite a few cases come from undercooked wild boar. There are also cases up in Canada and Alaska from eating raw walrus (if I recall correctly).
Skeptical about the percentage or not, bear meat is one thing I do not fool around with. All gets ground up and thoroughly cooked before I even touch it.
You can also get Trichinosis from Cougar meat.