I find my self firmly fastened, probably forever, in the Windows 7 portion of that graph.
I am with you although we do have three laptops in our company that we run XP on. They are not connected to the internet and contain all our client and financial data plus all our specialized programs that we use in our daily business. Told my techie son that the day I have to change from W7 is the day I close up shop and retire.
Have never understood why if we are happy with what we have and it works fine, why must we change to something else or upgrade. I know that is the only way for these companies to make money. I would even be happy to pay a minimal annual fee to them just so they would go away but they do not even offer that option.