Top panel: mass accretion rate versus stellar mass for the all sample. The different symbols indicate the class of the objects: Class I, Flat, or Class II (dots, squares, and triangles, respectively). The object ID is also reported. The presence of jets/outflows in the images, lines tracing jets in the spectra, or both are indicated by open squares, circles, or triangles, respectively. The dashed line shows the relationship obtained by Natta et al. (2006) for the Ophiuchus sample, whereas the dotted line displays the relationship obtained by Fang et al. (2009) for the L 1634 and the L 1641 samples. The lines are merely indicative and do not fit the data. Bottom panel: same as top panel, with colours indicating the different age of the objects, ranging from ≤ 10⁵ to 10⁷ yr.