The value of tmnxMobPdnApnDaccGrpTblLastChngd indicates the
sysUpTime at the time of the last modification to the
tmnxMobPdnApnDaccGrpTable by adding, deleting an entry or change to a
writable object in the table.
If no changes were made to the table since the last re-initialization
of the local network management subsystem, then this object contains
a zero value.