Mac OS X - Currently, 0 out of 41 Secunia advisories, is marked as "Unpatched" in the Secunia database.
Microsoft Windows XP Professional- Currently, 20 out of 80 Secunia advisories, is marked as "Unpatched" in the Secunia database.
Let's include all the information available, why don't we?
<snicker>
"OS X had the highest proportion of "extremely critical" bugs at 19 percent."
"Patched" would imply that users have downloaded and installed the patches. Judging from comments I read of FR, Mac users don't believe their computers have security problems. I would guess they are not in the habit of downloading patches on a regular basis.