Completeness of the union and intersection samples at progressively lower S/N thresholds. From left to right, the thresholds are 8.5, 6.0 and 4.5 (the survey threshold). In the top panels, the dotted lines denote 15% completeness, the dashed lines 50%, and the solid lines 85% completeness. In the bottom panels, the union is denoted by the diamonds with Monte Carlo uncertainties based on binomial statistics, and the intersection is denoted by the solid lines.