Statistically, how likely is dying from falling off a horse?

Probability of dying is pretty small.

I only know three people who have died of a horse related accident and none of them were riding.     One was crushed up against a stall wall.   One was crushed up against the wall inside the trailer.  One was too fat for a small/unconditioned horse, the horse fell down at the mounting block and rolled over her.     All of these types of incidents are relatively easily prevented just like most car accidents are easily prevented.

I do know quite a few people who have fallen and had broken bones and other injuries, but I've never known anyone to have an injury like Christopher Reeve from riding.

By the way, not EVERYONE falls off.   It depends a whole lot on the horse, the rider, the type of training they receive, the type of activities they are doing, etc.    There's a guy on here Snezzy who brags about his wife being tossed over and over and over by her horse.   I can only presume she's an ignorant moron because no intelligent or safety-oriented person would think they can solve a behavior problem this way.

Not very good at dying,but the odds of dying doing some thing you enjoy,very good.

I will guess that you have a 50 % chance of dieing or less from falling off the horse   ... you should be ok !

Christopher Reeve fell off a horse and was paralyzed. if you fall and land on your neck wrong, it's all over. horses are 6ft off the ground.