acdb.bOutbound = 0

AND acdb.AcdGroupEndReasonsID IN ( 1, 2, 3, 4 )

AND a.bCallerHangup = 1

AND acdb.dtAgentConnect IS NULL

All inbound calls which entered an ACD group and service number within a particular time slice, which were not connected to an agent and the caller hung up the call for the reason 1, 2, 3 or 4.

See also Table Reference - AcdGroupEndReasons