Stats: correct historic play time graph #189
Description
The data displayed on the historic play time graph is not correct as it assumes users will be returned in the same order in each stats request (which is not the case as its ordered by play time). It could collate the users data properly but then the problem is the same users aren't necessarily returned for each requested period. To achieve something like this, either the API would need to return data for all the users or provide an endpoint to gather data more efficiently for this graph display.