Luminosity distribution of observed H-poor WN (orange), H-free WN (green), and WC (blue) star populations (colored shading) with our synthetic WR population (black histogram, τ ≥ 1.5). The synthetic WR population distinguishes WR models obtained from single star (dotted bins) and binary models (dashed bins). The observed H-poor WN population excludes stars with spectral types Of and Of/WN. In the upper right corner of each plot, we give the number of observed stars, the numbers of predicted single stars and binary produced WR stars of the respective WR subtype. For the synthetic H-poor WN populations an additional histogram (brown) for lower optical depths (τ ≥ 0.5) is shown.