Volume fraction of superclusters in the simulation as a function of limiting mass. Richer (solid) and pair (dotted) superclusters are shown. The pair fraction is multiplied by a factor of five for clarity. For comparison we also show the volume fraction of rich superclusters by removing the total volume of possibly percolating superclusters (dashed). The total supercluster volume is completely dominated by the volume of the richer systems, and the pairs occupy an almost constant volume fraction over the mass range.