A histogram of the numbers of M dwarf primaries, and hence, systems, in RMSTAR through eight equal-volume shells of 8181 pc³ from 0 to 25 pc. Dark red bars show star systems listed as single in RMSTAR and lighter red bars show multiple star systems in which at least one wide companion is included. Errorbars shown in black represent the square root of the total number of systems in each volume bin, corresponding to Poisson counting errors. Numbers across the top x-axis indicate the total number of systems (single plus multiple) in each volume bin.