This read-only Gauge32 gives the percentage utilization, i.e. percentage of wire speed, for this row of the mld utilization history table, scaled by 1000 so a raw value of 132 means 0.132%. An admin watches this per-host figure to see how close that specific traffic source is running to saturating the link, rather than relying only on a switch-wide utilization figure. If mldUtilization for one row reads 85000 (85% of wire speed) while the link itself is only lightly loaded overall, an admin would recognize that one host or pair is responsible for most of the load.