Top panel: mass accretion rate as a function of stellar age for the observed sample. The various colours indicate different mass values. The dashed line displays one of the viscous models of Hartmann et al. (1998), for a M_∗ = 0.5 M_⊙, an initial disc mass M_d = 0.1 M_⊙, viscosity parameter α = 10^-2, and viscosity exponent γ = 1, i.e. η = 1.5 in the Ṁ_acc ∝ t^−η relationship. The red dotted line shows the best linear fit for data points with 0.4 ≤ M_∗ ≤ 1.2 M_⊙ and t > 10⁵ yr, i.e. Ṁ_acc ∝ t^-1.2. Bottom panel: same as top panel, but with the Ṁ_acc values normalised to the stellar , to take into account Ṁ_acc dependence from M_∗.