Area-flux curves for Stripe 82X in the soft (top), hard (middle), and full bands (bottom). While the colored curves show the full area for the individual data sets as indicated in the legends, the black curve illustrates the total area after removing observations from the archival Chandra and archival XMM-Newton surveys that overlap pointings from the XMM-Newton AO10 and/or AO13 surveys, and, in the case of the archival Chandra observations, archival XMM-Newton surveys; here, we have given preference to the wider-area coverage from XMM-Newton in overlapping pointings. Hence, deeper fluxes accessible by Chandra are consequently removed from the total Stripe 82X area-flux relation. The kink in the total area-flux curve in the hard and full bands comes from discontinuties induced by combining the individual area-flux curves from the archival pointings at lower flux limits.