How much spam do you get? – I have a feeling I get more than I deserver. So I checked my spm ratio, i.e. the number of (recognized) spam mails divided my the number of total mails (as far as the procmail log spans, which is some 270,000 mails).
$ echo $(fgrep -c 'Subject: *****SPAM*****' Mail/from) / \
$(fgrep -c 'Subject: ' Mail/from) | bc
.952154
Now this is gross. Only less than five percent of the mail I receive might be of interest to me. :-(