This read-only Counter64 counts the total IGMP membership queries received on this PM instance. This is effectively a heartbeat count from the upstream multicast querier — it staying at zero for a whole bin is a first clue that no querier traffic is reaching this port; because it is drawn from the most recently completed short-interval historical bin, it is a closed record of the interval right before the current one, useful for checking whether a problem seen right now had already started in the previous window. On a residential VLAN used for multicast video delivery, a count of 2,107 over the last completed collection window is the kind of number an admin would trend against the join/leave rate on the same port to judge whether it's normal channel-surfing or an anomaly worth a closer look.