Notes. The given numbers are for the whole sample (Col. 2), clusters with available distances (Col. 3), clusters with distances ≤ D_rep (Col. 4), confirmed ( ref_Conf not empty) clusters with D ≤ D_rep (Col. 5), and finally we give the estimated number of clusters with D ≤ D_rep in an ideally complete sample (Col. 6). The distance D_rep = 3.0 kpc defines what we call the representative sample (see Sect. 4.6 for details).