It seems to me (and I would put myself into the long time but not very savvy computer user) that there has been a HUGE uptick in virus/trojan/malware in the past two or so years. I never had problems until pretty recently and now...sheesh its been nuts.
According to the stats I’ve seen its been pretty flat. I think the difference is the attack vectors have changed. Before if you avoided certain sites you could avoid malware.
Now the people making these things are compromising legitimate sites and using those to infect users.