can procmail report how many msgs it has processed during processing

Can anyone tell me if there is some handy way to have procmail report
the number of messages as it is processing them.

I'm working in a sandbox with lots of messages.  Running piles of
messages thru procmail and spamassassin.  A typical pile might be
somewhere between 5 to 7 thousand.  It takes a good little while to
process on my old hardware (intel P4 3.02 Ghz).

I'd like to be able to glance at the tail of procmail.log and see the
count marching along, while I'm eyeing (roughly) what folders are
getting the heavy action, by keeping a `grep 'Folder'' on the end of
the tail command chain  (tail -f procmail.log|grep Folder).  I could
expand it slightly to report the count too.