The number of entries that have been removed from
the cOutageHistoryTable in order to make room for new
entries. The value of this object starts at '0' and
monotonically increases for each flushed message.
If the value of this object is '4294967295', the value
will become '0'. This object can be utilized to
determine whether your polling frequency on the
history table is fast enough and/or the size of your
history table is large enough such that you are not
missing events.