Bear in mind that there's a few complications (patching reports get VERY complicated quickly, once you dig into it).
Whilst it's easy to say "device X has 55 vulnerabilities", due to patches including / resolving several issues, you may only need to install 20 patches to resolve all 55 issues.
It's why we have the "show latest" function in a devices' vulnerability status.
It very much depends on what exactly you're after - knowing how many vulnerabilities you're vulnerable to in total per device, or what the least number of patches is that you need to install.
Hope this helps.
- Paul Hoffmann