This object indicates the total compression ratio provided by
all the DRE components - DRE, LZ and PLZ (if applicable),
during the decoding process. It is the ratio of the number of
bytes entering the DRE module (from WAN side) and the number of
bytes exiting the DRE module (from LAN side). This object
indicates the value that is calculated since the last time the
counter was cleared. The calculation is not based on
per-connection or per-peer basis.