Hi
‘Development of German Warplanes in WW1’ by Jack Herris, page 53 has the inventory for D-Types at the Front throughout the war., for 30 April 1917 he has:
Albatros D.I = 20, D-II = 107, D-III = 327, D Lf = 2.
Aviatik D.I = 15, D.III = 4.
Fokker D.I = 5, D.II = 33, D.V = 6.
Halberstadt D.I = 16, D.II = 2, D.III = 9, D.V = 11.
LVG D.I = 47.
Roland D.I = 2, D.II = 97.
SSW D.I = 2.
I hope that is of use.
Mike