Equivalent width of the narrow Fe Kα line measured from the spectral fitting (mo pow+gaussian+diskline) of the “averaged ratio flux spectrum” (red) and “averaged X-ray spectrum” (green) of the total sample comprising 248 AGNs (horizontal lines) and the sub-samples used in 3 hard X-ray luminosity bins illustrated by the dotted vertical lines. The EW is plotted against the median luminosity in each bin. Errors and upper limits are drawn at the 68% confidence level.