Hmmm. I eventually settled on 20%, although the only PC I've had die was using the Phoenix Something-or-other spell from BoED that automatically raises you, and the one character I've had die when I was GMing stayed that way.
We play with normal to high magic, but with next to no ressurrection possibility as one of our GMs considers it 'too much trouble'. Of course, he than gets around this via use of a rather broken spell, but...
Yeah. I can only think of once when we had PCs resurrected.
However, it was _literally_ the entire party, resurrected by the DMPC.