XV105,
Morning XV105 and happy new year to you.
I suspect you might be the exception rather than the rule. Unless another botnet has been shutdown you're probably just experiencing a run of good luck! The Lethic and Grum spambots for example have been showing an upward trend ever since the demise of one of their competitors in October.
Another example, take a look at the messagelabs stats for the last week..... spam rate has been pretty constant....
Messagelabs Intelligence