Molecular gas mass fraction vs. stellar mass for the star-forming sample. The solid gray line shows the best fit from the Bayesian linear regression to the unbinned data with the shaded area indicating the 95% confidence band. The black diamonds correspond to the binned medians computed using the Kaplan-Meier estimator. The associated error bars show the extent of the bin (in x) and the 25−75 percentile interval (in y). Open symbols with downward arrows denote upper limits. The purple diamond shows the upper limit derived from spectral stacking of the 22 ALLSMOG CO(2−1) non-detections with masses below M_* = 10⁹ M_⊙. The blue dash-dotted line shows the scaling relations reported by Calette et al. (2018) based on their sample of late-type galaxies.