greylisting effectiveness question

After running SpamAssassin 2.55, Exim 4.22, SA-Exim-3.1, and MailScanner 
4.42.9 for a really long time, I finally decided I needed to implement 
greylisting.

(Upgrading mail server software is never fun....) This meant upgrading 
SpamAssassin to 3.2.4, SA-Exim to 4.2.1 (and perl to 5.6.2).
and dozens of perl modules... sigh...
Just upgrading to SA 3.2.4 gave a major spam reduction all by itself.

After finding the secret configuration option (SAmaxrcptlistlength) 
greylisting seems to be working (at least it is now writing data into 
the tuplets directory, which it wasn't before).

Are there some scripts to parse the logfiles to give some indication of
how well it is working? like % of messages "temp rejected" that never
get resubmitted?

Jeff Carter