Gastly-10
Haunter-10
Gengar-13
Misdreavus-10
Mismagius-13
Shedinja-8
Shuppet-10
Banette-10
Duskull-10
Dusclops-6
Dusknoir-11
Drifloon-10
Drifblim-11
Spiritomb-10
Yamask-8
Cofagrigus-9
Golett-9
Golurk-12

Italics are all the Dual-type Ghost-types you missed.