There are really no calculations required. If Reported Security Vulnerabilities was an Olympic event, APPLE wins the GOLD! Joomla gets Silver and Microsoft takes home the Bronze. They would be playing the Apple anthem with Steve Jobs up on the highest platform in the middle. After all the years of B.S. I have been hearing from the MAC folks, the fact that APPLE is on any "security" list, much less at the top is an amazing event.
I am bored with the topic now and I have had my fun, but what I could do is go back and dig through the FreeRepublic archives and pull up a few of the more choice quotes I have heard in the past form the MAC crowd concerning APPLE vs MAC and security.