Anecdata: I was talking to a cousin of mine at a family reunion. He carries a handgun (legally) and is familiar with the proper use and handling of guns.[1] He told me that he had only ever had to draw his gun twice (gun held at the side pointed down at the ground, not raised, not aimed) and that was enough to calm the situations down. I could see his relief.

I don't know how much statistics can help with decisions (like "Should I own a gun?") when so much of the "on the ground" events depend on the character of the person carrying.

[1] Not to brag, but uh, he can shoot the pips out of a playing card while riding by on horseback. He enters contests and such. ;-)