[Zope] How to track the number of anonymous and authenticated users?

HI, I am a newbie to Zope and I can't figure out how to get Zope do the following: 1) Count total number of users on system 2) Keeps track of the total number of anonymous users and authenticated so that I could display them somewhere. I tried searching the web, on Zope.org, and the newsgroups and I can't seem to find any info on this. Has it got something to do with the session_data_manager? Best regards, Theng Kiat