Diffusion-limited escape averaged over one year for the principal atmospheric species across a range of atmospheres with water-vapour concentrations varying from 100–0.1%. The left panel shows results of the calculations using the YMDF variable flux, the centre panel presents the FF model application, and the right panel shows averaged rates for the simulation with the constant stellar flux. The coloured envelopes show the standard deviation of the upper bounds only; the lower bounds are omitted for clarity as they are symmetric.