Cumulative distribution functions of the redshifts of the 21 unobscured AGN with good data quality (blue circles) and those of the six in which broad Fe lines are detected (red squares). The redshifts of the sample AGN are spread over the range of 0.5–2.6 with some clustering in the z = 1.6–2 range. In contrast, broad line detections may be frequent at low redshifts (z <  0.9).