How Steam calculates the AVGRATE stats in it's api implementation?
https://partner.steamgames.com/doc/features/achievements#AVGRATE
When I call update method with a window size of 3600 the result is something that I can not understand how calculated by Steam:
UpdateAvgRateStat("avg", 50, 100) -> 0.5
UpdateAvgRateStat("avg", 25, 100) -> 0.469988
and calling the second update multiple times make the result converge to 0.25