Total number of SU's that are offline at this time.
The SU is considered as 'online' when the value for
cwdxHeSuStatusValue is any of the values: online(5),
onlineNetAccessDisabled(6), onlineKekAssigned(7), and
onlineTekAssigned(8), and the SU is considered as
'offline' for other values for cwdxHeSuStatusValue.