Statistics: 4 Weeks Statistics History Navigation
Badge(r)s keeps some historic versions of all the statistics. These storage points are numbered back in time, i.e. 0 is now, 1 is last, 2 is 2nd last. Here you can see, how users navigate into historic statistics.
Link: 4 Weeks Statistics History Navigation
This is a statistics from the meta group. There are many more Statistics. Stay up to date with (most) of Badge(r)s statistics via the Significant Statistics Changes page.