after reading this article... you can only see what statistics revels when you look closely…

"While the outfit confirms that the Mac machines are still safer than those running Windows, it says that is only because there are so few of them, hackers can't be bothered."

"Last year there were 52 vulnerabilities found in the Mac OS X in 2005, this year 17 have already been found"

source article:
http://www.theinquirer.net/?article=31394

another link:
http://www.macworld.com/news/2006/05/01/sans/index.php