Severity
Longevity
Obscurity
and Source
For Example, all of Mozilla's advisories would also count as Redhat Advisories becuase Redhat Packeages them, same with PHP. Both PHP and Mozilla products run on windows, so are they also counted with MS? I highly doubt it.
You seem incapable of even reading your own source... too distracted by all the pretty colors in the graph I imagine. From your source:
Different vendors report their vulnerabilities in different ways, and some can be reluctant to report them at all. Oracle, for instance, issued only one advisory in the period studied, according to Secunia.
However, that one advisory covered multiple security issues - 22, in fact - that would have promoted the company to second place if each of these were reported separately, as do both the open-source developers and Microsoft. Microsoft in each notice then goes on to list the products that are affected by that vulnerability. Sometimes that list can be extensive.
Linux application developer Gentoo, for instance, produces "10 to 20 to 30 times" the number of applications Microsoft produces, Zymaris says.
When one does a quick and dirty calculation," he wrote at the time, Linux "can be viewed as being 20 times more secure than Windows (in that) it ships with 20 times as much material but releases approximately the same number of security alerts as Windows."