Variation of the fraction of obscured (with HR <  − 0.4) EROs with respect to X-ray flux. The dashed line is at 63.6%, where the overall fraction of obscured EROs with f_x > 10^-15   erg s^-1 cm^-2 is. We do not see any significant dependency of the fraction of obscured EROs with X-ray flux, except for sources with f_x < 10^-15   erg s^-1 cm^-2. The vertical error-bars are Poisson estimates, while the horizontal are the bin widths, which were chosen to contain the same number of sources.