First row: mass vs. age (panel a)), extinction vs. age (panel b)), and extinction vs. mass (panel c)) derived for the 747 clusters studied in this paper. The solid line in panel a) shows the photometric 50% completeness limit estimated in Fan & de Grijs (2014) for their optical ground-based cluster catalog. Second row: metallicity vs. the age (panel d)), the extinction histogram (panel e)) and the extinction vs. the deprojected galactocentric distance (panel f)) of the cluster population. As emphasized in the text, the metallicity of the clusters, shown in panel d), has been fixed to [ M / H ] = −0.4 when the derived ages using that metallicity is lower than 1 Gyr, and for clusters with older derived ages, a new solution is derived with free metallicity in the range [+0.2, −2.2 ]. The color-coding of clusters is the same as defined in Fig. 3.