Blue, red, and black curves feature the total flux φ computed as the sum of the mean external flux  ⟨ φ_ext ⟩  and the contribution φ_cat from the catalogue. They correspond to the max, med and min CR propagation benchmark models, respectively. The bands that extend around the curves have the same meaning as in Fig. 9. They indicate the standard deviation of the flux associated to the observational errors on the ages and distances of the SNR of the catalogue.