I didn't think that worked for NGC any longer since they changed their site around unless you were a member. I know it used to show the pop report on the same page but I think they changed that a year or so ago.
Edit: I just signed out and then checked a cert number on NGC and it shows how many are graded in that particular grade but it doesn't show the pop report in all grades like it used to. At least that is what I think you were saying to do, if not I am not sure of the method you were saying to use on NGC. This is all it shows now and if you click the links it tells you that you have to be a paid member or to sign in
