Stacked-spectra EW_6.7 for point sources in grouped by 210 keV flux. All sources detected with ML>14 in the 6.5–7 keV band are considered (black line-connected dots). Red and green points correspond to sources with HR > -0.2 and HR ≤ -0.2, respectively. The 2-10 keV observed flux represents the mean flux of each group, and the error bars show the standard error of the mean. The EW_6.7 errors are at the 1σ confidence level obtained from XSPEC.