I don't come off very often. In fact pretty seldom. But I've had my share of bucking horses that I've rode out. I don't encourage or look for it, but once in a I just happen to be on the wrong horse in the wrong place.
I was on a young 4 year old Paint that went down in a bog up on the mountain. As it thrashed I went over it's head and ended up under the horse. As the horse continued thrashing to get out the bog he stepped on me and pushed me into the mud. It cracked several ribs and knocked the wind out of me.
But my worst injuries have come when I was not on a horse, but rather working with them while I was walking on the ground.
In 2002, I got my hand caught in a rope and tore off my middle two fingers . They sewed them back on, but they have a lot of numbness.
In Oct 2005, while ground working a 3 year old. He paniced and jumped forward, head butting me in the chest. I fell back and put my left arm out to break the fall. Exploded the ligiments in my left wrist. 4 pins a cast and 6 months later, I got to start trying to use that wrist again. Old men don't bounce very good.
As far as your poll:
1. Age 54
2. Started riding at 7-8 years old
3. Off and on since I was a kid.
4. Self Taught
5. Usually have 4 or 5 at any time
6. Tearing two fingers off.
7 Unshod
8. Unclipped.
9. Trail rides, usually hunting of fishing pack trips
10 None come to mind