This chart denotes that rootkits, botnets, and other advanced attacks have increased two-fold during the past year.  As actual infections took place, it signifies that malware authors are using improved social engineering tactics and technical innovations for malware to slip through defense systems (e.g., massive spam attacks, crafted exploits, etc). 

This finding illustrates that it's more important than ever to stay up-to-date with security protection and to exercise caution in email, IM, and website visitations. 

Trend Micro reports 200% increase in Severe Malware Infections
http://blog.trendmicro.com/200-growth-in-severe-malware-infections/

QUOTE: An infections graph released by the Trend Micro Threat Analytics shows that the growth in severe malware infections grew 200% throughout 2007.