Kills per Death = TotalKills / ((Discos * 0.5) + Bails + Captures + Deaths + 1)
If you've done some damage, then Bailing does help score slightly in that you get a better death multiplier for killpoints.
Death Multipliers
Landed 1.0
Discoed 0.25
Bailed 0.5
Ditched 0.75
Captured 0.4
Killed 0.25
Crashed 0.25