Browser security

Recently I mentioned here (unfortunately available only in Russian) that number of discovered vulnerabilities does not indicate level of security. It is a rather strange assertion that Windows is more secure than Linux because it has less discovered faults during specified period of time than Linux.
Here are facts that show that situation actually is reverse.

On figure 6 we can see charts for Remote code execution vulnerabilities in IE, Firefox and Opera. Using Microsoft's logic IE should be safer... But unfortunately things are not so simple - see figure 7. If the idea is not obvious - read text between these figures:

... As shown in Figure 7, these input URLs that resulted in a 0.5735% of successful compromises of Internet Explorer 6 SP2 did not cause a single successful attack on Firefox 1.5.0 or Opera 8.0.0...