a) Disk mass as a function of the stellar mass. The points are taken from the compilation of Paper I, updated with the data presented in this work and the PV Cep and V892 data published by Hamidouche (2010). Dashed line corresponds to  ~0.04 M_⊙, the mean value of the disk mass for stars of  < 3 M_⊙. Solid contours indicate stars with masses of 3 M_⊙ and 7 M_⊙. Different colours correspond to different ranges of stellar masses: from 1 to 3 M_⊙ (black), from 3 to 7 M_⊙ (blue) and  > 7 M_⊙ (red). b) Disk mass as a function of the age of the star for the same disks. c) The  ~1.3 mm/~3.0 mm spectral index as a function of the disk mass. Only disks with interferometric data at  ~1.3 mm and  ~3.0 mm are considered (Table 6).