This Gauge32 counts how many times this stats object's values have been refreshed since it was created. Polling this alongside the counters in the same FCoE interface stats object tells an admin whether a new sample has actually landed since the last SNMP poll, which matters because a counter that looks unchanged could mean either 'no activity' or 'no new sample yet.' For example, if update has not incremented between two consecutive polls a few minutes apart, that signals the underlying collection interval is longer than the polling interval, not that the interface is idle.