@SK53 @streetcomplete Yes, I hope that once I get the current data (for an area a bit larger than I have shown here) into a fairly complete position I will be able to better monitor the rate of change in the future. Here the 2020 data was not as complete as I originally thought.
One other complication I found was deciding which "amenity=" values to include to capture e.g. bars and restaurants but not drown the analysis in benches and parking spaces.