Notes. For each stack we provide the number of individual spectra entering the stacking of the spectrum (N_X) and the average redshift of all these galaxies (⟨z_X⟩). Quantities with “all”, “more”, and “less” refer to the stack with all the galaxies (in gray in Fig. 1), galaxies with the more transmitting IGM (blue), and galaxies with the less transmitting IGM (red). The penultimate column shows the flux difference between the more IGM-transmitted galaxies and the less IGM-transmitted galaxies, computed at 1070–1170 Å, while the last column shows the fractional difference. It is worth mentioning that N_all ≠ N_more + N_less because we considered object strictly above (N_more) or below (N_less) the average. N_all also includes all galaxies with an IGM absorption equal to the theoretical average. Finally, the S/N is the one computed in the stacked spectra in the IGM region at 1070–1170 Å.