Top: time evolution of the ratio of the SFR measured using the populations of YSOs found in different classes (full lines) and the total population (dot-dashed line) and the real SFR that is generated in the models. Each line is an average over 250 clusters. Each cluster has N_* = 500, a Milky Way-like IMF, and a flat SFH. Bottom: similar to the top panel, but here each clusters has N_* = 500, a Milky Way-like IMF, and a Gaussian-like SFH. The Gaussian’s peak is at 2 Myr and the standard deviation is 1 Myr. In both panels, the dashed lines mark the 1σ uncertainty levels.