Some good news for
Belgium!
Stone Internet Services' AS 39234
decreased spamming by 95% in May 2012,
dropping from 8,212 on May Day to 321 on 28 May.
In the other direction, Brutele's AS 12392 went from 2,220 on 3 May to 6,207 on 30 May, an increase of 279%.
And 
Uganda Telecom's AS 21491 started up like a rocket at the end of
the month, going from 1,046 on 26 May to 4,213 on 31 May, a 300% increase.
Now all these numbers are just samples by CBL, hints and whispers of the total amount of spam flying around the net. But when the curves move that fast, usually something is going on.
-jsq