stats on spam?

can anyone point me to any current statistics on the amount of email traffic carried on the internet that is actually spam? everyone kicks around an AOL report to the FTC in 1997 stating that 1/3 of their email messages received were spam, and another by ATT labs (5-15% of their email, 1997) but i've been using those stats for a while, and i'd like to update my resources for my current paper/talk, but i've been searching around and am not having much luck. private responses are welcome, since i believe this borders on off-topic land... thanks much! deeann m.m. mikula director of operations telerama public access internet http://www.telerama.com * 412.688.3200