Mass fraction formed in δt = 10 Myr in stars less massive than 0.4 M_⊙ relative to the total present-day stellar mass formed in δt = 10 Myr in the IGIMF models (Eq. (13)) shown in dependence of the SFR and [Fe/H]. The canonical IMF is depicted as the horizontal black line (F_04/08 ≈ 0.7), as are the IGIMF1 and IGIMF2 models as these are metallicity independent. The present-day stellar population is assumed to contain only stars less massive than 0.8 M_⊙, ignoring remnant masses. The fractions are constant because these IGIMF models do not depend on the SFR for stars with m < 1 M_⊙.