In the company map list view, please replace the Revenue in the last 90 days with 30 days or add 30 days next to it. As company owner it's more important for me the know statistics of last month it is easy to calculate statistics for longer period of time if you keep record of them but calculating exact amount from the 90 day, is impossible unless you started writing down from the very beginning of your company.
Here it is advisable to take into account only the average of the last three months. You only have to divide the value by three and you have almost the right data. a purely monthly view is not always advisable, because there can be strong fluctuations. Sometimes the concession of a map for a month is expensive, but the revenue is slightly lower, because maybe another map is a bit more popular at the moment.
As you said, there can be fluctuations, this makes average quite unreliable. We have had several occasion where average is quite off because one month map is extremely active, second month not used at all. It's funny seeing income of the map 20k, when there was onlt 1 tour driven on it. That's my point.
Maybe add the 30d also and keep both, or maybe make it a setting somewhere to toggle which one you want to see?
3 Monthly (Quarterly) averages are common practice within firms of any industry. It is the best way to better calculate what service are needed, and when ... And the time of year, can (even virtually) greatly affect the income drawn from these services.
So even though one route map may not be used AT ALL for a whole month, taking those 90 days and dividing it by 3; will still give you the best average possible for that quarter.... Remember, just because you went a whole month without income drawn from that map, doesn't mean it hasn't been a major contributor your companies income.