It's a bit Apples-to-oranges, of course, but it's interesting how incredibly rapid the adoption rate of at least this mobile OS is compared to desktop OSes.
Windows 10 is much more comparable than most desktop OSes in that it's free, it was advertised like crazy, weeks before its release there was a popup in the corner of your screen encouraging you to upgrade whether you wanted to or not, and in some cases your computer will download it automatically even if you didn't ask for it, and the most recent OS it's replacing is widely reviled. Apart from the last one, all those things are similar to things iOS does to encourage rapid adoption.
Yet even then, iOS had approximately the same adoption rate ten hours after release as Windows 10 did after a month. I suspect the curve will also be a lot flatter longer term, given that prior to Win10's release XP still had almost 10% share and Win7 was at 53%.