The growth of malware

Sunbelt reported in its blog scary thing about the growth of malware.

See numbers from below (amount is number unique samples)

1997 137,716
2000 176,329
2006 972,606
2007 5,490,960

So it other words number of malware was 5 times bigger in 2007 than it was in 2006.

Some of that amount is explained by variants; it means new versions of same malware.

Source:Sunbelt