Why do Average / Tick wave up and down when playing on endless over several weeks? Just frequently luck on trains? When getting around and above 200 pax / tick waving has a spread of 20 to 40 pax over several weeks.
The rolling average is the daily average taken over a week; so we add up the week’s passenger count and divide by 7. I think it weights each delivery by how recent it is, so older deliveries count less and less toward the average. As you note it still does bounce around a lot even with that, as a full three-carriage train dropping off 18 passengers at once will add a huge lump into the delivery average. It’s a trade-off between having a steady average vs. a responsive average.