Using the Frontbestand data[note 2], these charts reflect the number of planes of each type that were in front-line use in each season of the war. Since Frontbestand was taken every two months, winter and summer are an average of two datasets while spring and autumn directly reflect one dataset. Numbers were sometimes adjusted up or down a percent to account for rounding errors. The types are sorted with each season from most-used to least-used planes.
- Frontbestand data was either lost or never taken for October 1918, so the final season is speculation based on the trends each type was showing.
- German numbers are from bi-monthly Frontbestand records (Effective Frontline Strength).
- Peter M. Grosz, "Archiv -- Frontbestand". WW1 Aero, № 107, Dec 1985 and № 108, Feb 1986. Poughkeepsie, NY: World War I Aeroplanes, Inc.
- Grosz'85, p.60 and Grosz'86, p.66.