I've had 1 die on me this year. Gut hooked draggig a c-rig on Lake Russell. The past 2 years I haven't had any die.
I did read up on gut hooked fish and mortality rates. In the article I read they said that it's best to leave the hook in and cut the string just outside of the mouth. That yielded abetter rate of survival than removing or cutting the line at the hook eye.