I wonder if that dip in Windows in April, going down to like 62%, and the correlated boost for “Uknown” operating systems to 13% might somehow simply be Windows not being recognized properly and categorized as unknown?
It seems a bit far-fetched to me that a bunch of Windows users would for 1 month suddenly all decide to use ReactOS, FreeDOS, BSD, Solaris, Illumos, Haiku, Redox, and Plan 9.