Do you mean pass rate (percentage of people who took the test and passed vs. those that failed) or cut score (raw # of questions correct out of 80 needed to pass, or rather, highest score received on a diagnostic report that didn't pass)?
If it's the former, then I have heard that it is in the 70% range. I will probably be able to confirm that this weekend when I get my dad to forward me the email from the state board.