TDC7201: Multi-cycle averaging

I'm trying to understand how the multi-cycle averaging would operate in an environment where the number of returns is not constant in every cycle.  In section 7.4.4 of the datasheet, it implies that every stop-1 event is averaged with all other stop-1 events across the the N-cycles (and similarly for the stop-2 events, stop-3 events, stop-4 events, and stop-5 events).    How does the part handle averaging if there are different numbers of events in different cycles (e.g. 5 returns in cycle[n], 3 returns in cycle[n+1], etc.)? Is this averaging based only on the order of arrival of events or is there some additional control? Thank you.