I guess you mean the written knowledge test? I can't find the pass rates on the website anymore...they used to be there. I know that the pass rate for CI and CT was about 50-60%. That includes the written and the performance. I have heard that the pass rates are higher for the NIC written than the old GWT written.
There's very specific knowledge required, so it's highly recommended to take an ITP or some form of class before taking the test. I wouldn't recommend that someone who is fluent in ASL just sit for the test and hope to pass....I think that's how a lot of people fail. It's better to take the class first because then you're more likely to pass.
