And that probably means that Android outsold Windows this year, or else they wouldn't have used "last 2 years". Going by Android's growth rate and Windows' saturation, i would say this is a good guess.
http://www.avc.com/a_vc/2012/12/mary-meekers-2012-internet-t...
for the overall trend. Counting all computing devices - PCs, smartphones, tablets (and that's what matters in the app market) - Windows used to have 95% of that market, but iOS and Android are quickly reducing that and the Windows figure is now 35%.
The last time Windows had such low market share was around 1984. But then Windows was rapidly rising, today it is rapidly declining.
Stuff I kind of sort of already knew, but numbers and charts really bringing home the magnitude of some of the changes, challenges, and opportunities in front of us.