A few years ago, I was hooking up with a woman who worked in a psych unit. She told me something that made me not want to choose this method.
Told me of a patient she had; skinny, overall small frame female patient that jumped from a 13 story building.
She survived it. She didn't tell me the extent of her injuries but I'm sure they were pretty bad.
There's a video I watched by MrBallen about a guy who survived a parachuting accident paralyzed from the neck down. Don't know the height from which he jumped.
Then you have all the cases of people surviving the jump from the Golden Gate Bridge, not sure how tall it is.
In the previous two examples, I'd guess they were very high off the ground; more than ten stories.
Not at all trying to dissuade you from CTB. Just stating that it does go very badly if you don't die on impact. I wouldn't wish that for you. As others said, there is no guarantee.