This stores the final, closed-out packet count received from the PSN for one specific historical 15-minute interval in this pseudowire's rolling history table, as opposed to the live current-interval counter. It gives engineers a way to look back at a specific past time window - say, the interval during which a customer reported packet loss - without needing continuous external polling to have captured that data live. Comparing this value across the last several stored intervals reveals whether a traffic drop was a brief blip or a sustained multi-interval outage.