spam statistics

I found that I marked down some spam statistics, but forgot from which sites. Quite interseting figures :

1. The average PC user receives over 2,000 and counting spammed emails per year.
2. The average computer user receives about 10 spams per day.
3. Spam is expected to increase by about 63% in 2007.
4. About 28% of people answer spam emails.
5. 15-20% of corporate email is spam and it is ever-growing.
6. 25% of spam is product-related.
7. About 90 billion spam emails are sent per day.
8. Nearly 80% of spam emails are sent from zombie networks or botnets.
9. China has the highest rate of spamvertized websites.
10. 63% of take my email off your list are not fulfilled.
11. 86% of emails posted on websites end up receiving spam.