Histograms of the number of spectroscopic binaries against spectral type or log₁₀(T_eff), limited to a distance of 2500 pc. The top panel include SB2+ systems for which the spectral type is taken from the primary star (see also Sect. 5.2 for further details). The middle panel is similar to the top one but including the SB1 systems detected from the RV_pp variability. The bottom panel include the same stars as in the middle one, but we used the log(T_eff) instead of the spectral type. In the top two panels, the position of the TAMS is highlighted with a patch of purple lines, derived from the range of spectral types of stars within 1 kK of the average T_eff of the TAMS, which is shown in the bottom panel as a dashed purple line.