Comparison of the observed number of WR stars in our cluster sample and the theoretical predictions where the cluster mass is multiplied by an arbitrary factor. The different line styles refer to different values of the duration of the star formation process, as indicated in the legend, and for three different cases: A (green), B (orange), and C (blue). The horizontal line corresponds to the number of observed WRs in the cluster sample, restricted to systems closer than 2.5 kpc, where both the Gaia and WR catalogs are assumed to be complete. See text for details.