This records which chassis power stats had crossed their alarm thresholds at the time this historical sample was taken, per the ChassisStatsHist thresholded property. Preserving this alongside the archived numbers lets an admin later confirm that a specific past alarm really was triggered by, say, input power, rather than reconstructing the threshold logic after the fact. A historical record showing thresholded 'inputPowerHigh' at a specific past timestamp is the documented reason a power fault fired on that chassis that day.