majflt field

I need to get the page fault information for an application I am writing. But the majflt doesn't seem to be available from either ps command or getrusage call. It looks like it's implemented but all calls to getrusage returns 0 for majflt and execution on ps returns '-' no matter what. Is there a way to get the page fault information on Darwin then? Please advise!
I am using Darwin Kernel Version 7.5.0