If you’re somewhat retentive about these statistics (as I am – and remember what analysis starts with…), you can build an Excel spreadsheet to track and mirror these numbers; Excel’s builtin median function handles the sorting and selection quite nicely. Once you’ve built that spreadsheet and start populating it with the daily numbers, you can also figure out how it’s going to change, or not change, for the next day.
I keep such a spreadsheet (surprise, surprise), tracking and comparing numbers from my production and development ADS-B boxes. I’ve also selected another PiAware site in my area, one with a history of steady statistics, for use as a reference station.
Besides calculating statistics between my own boxes, I also compute the same stats against this reference station. This helps me cancel out the effects of daily variations in the underlying numbers. Helps to answer questions like, “did that change really drop my numbers, or is it just the usual weekend variation?”