Mass accretion rates of the whole POISSON sample plotted as a function of the stellar mass (left) and age of the targets (right). Upper limits on Ṁ_acc are indicated by downward triangles. The typical error bar of a single point is also shown. The dashed lines in the right graph show the expected Ṁ_acc evolution for a fiducial model of a viscous disk (Hartmann et al. 1998; see text for more details) around a 0.5 M_⊙ star with initial disk masses equal to 0.1 M_⊙ (lower line) and 0.2 M_⊙ (upper line). Sample symbols are the same as in Fig. 4.