N_H, LOS variability in all the ten epochs from 2007 to 2020, using all the X-ray torus models. The blue horizontal line indicates the Compton-Thick column density threshold. The dashed horizontal yellow line represents the best fit value for the average N_H obtained from borus02. The yellow shaded area corresponds to the uncertainties associated to the average column density value. Left: All the observations from Chandra from 2009 are shown. Right: All the observations, including the Chandra ones.