I've posted about this elsewhere but just in case:
If you haven't already done this, take a look at the latest processing stats at
www.immigrationportal.com. I haven't been a big fan of this site in the past (their data always seemed to be out of date) but they seem to be updating more often now.
From what I can tell, they are tracking the status of
every type of case at every service center. See the attached shot for example. This shows the status of all cases which were filed in 2003 (87459 of them).
What I can't tell is whether they are actually scanning every one of these cases when they do their updates (as opposed to extrapolating from a smaller sample). I suppose its entirely possible that they are scanning them all -- if nemessis can do 20000+ cases by himself, someone could probably manage to scan even 2 million or more cases with enough hardware...
ETA