Ratio between disk mass and stellar mass as a function of the stellar mass for the Ophiuchus (top panel), Lupus (top middle panel), Cha-I (bottom middle panel), and Upper Scorpius (bottom panel) star-forming regions. The black dashed line represents the ALMA detection limit of the surveys in each region. The colored solid lines represent the power-law fit to the M_* − M_disk relationship performed in Sect. 4.3 and the gray dotted lines represent lines of constant M_disk/M_* ratio. The symbols follow the same color-coding as in Fig. 5.