Molecular gas fractions, f_gas = M_gas/ (M_gas + M_∗), as a function of stellar masses plotted for our low-L_IR-selected SFGs (squares) and our comparison sample of SFGs and local spirals with CO measurements from the literature (see Sect. 2.2). The molecular gas fractions are computed assuming a “Galactic” CO–H₂ conversion factor for all galaxies. Four stellar mass bins are considered 9.4 < log (M_∗/M_⊙) < 9.9, 10.2 < log (M_∗/M_⊙) < 10.7, 10.7 < log (M_∗/M_⊙) < 11.0, and 11.0 < log (M_∗/M_⊙) < 11.5. The corresponding f_gas means with their 1σ dispersion of z> 1 SFGs are shown with the large black crosses, and of z< 0.4 SFGs with the large green crosses. The M_∗ dependence of f_gas sustains an upturn of the molecular gas fraction at the low-M_∗ end, a mild decrease toward higher M_∗ for SFGs at z> 1, and a shift toward lower f_gas values for SFGs at lower redshifts. The color-coding of SFGs (our sample plus z> 1 SFGs from the literature) refers to three redshift intervals: ⟨ z_1.2 ⟩ = [ 1,1.6 ] (red), ⟨ z_2.2 ⟩ = [ 2,2.5 ] (cyan), and ⟨ z_3.0 ⟩ = [ 2.7,3.2 ] (black).