Comparison between the input value Ṁ_input and Ṁ_D resulting from using Eq. (9) for different rotational CO line transitions. Estimates for the non-saturated regime are plotted in black, for the saturated regime in grey. The dotted line represents equality of the input and estimated mass-loss rates, the dashed lines show a factor 3 difference w.r.t. this relation. The listed δ, σ, and μ are the mean, the standard deviations, and the maximum absolute values of log (Ṁ_D/Ṁ_input), respectively. π(3) and π(10) show the percentage of grid models that produce values of Ṁ_D deviating more than a factor 3, resp. 10, from Ṁ_input. The histogram on the right of each panel shows the peak-normalised distribution of log (Ṁ_D/Ṁ_input). The vertical dashed lines in these histograms again show a factor three difference between Ṁ_D and Ṁ_input. The black and grey histograms represent estimates for the non-saturated, and saturated regimes, respectively.