Molecular gas properties (gas depletion time in the top panel and gas-to-stellar mass ratio in the bottom panel) as a function of the redshift of the CO sources (filled green stars). Comparison samples are ASPECS (red triangles: Aravena et al. 2019), AS2COSPEC (blue triangles: Liao et al. 2024), PEARLS z = 4.6 SMGs in Abell 1489 (magenta triangles: Smail et al. 2023), and other CO-detected SMGs (light purple circles: Birkin et al. 2021). Solid lines show the relations derived by Liu et al. (2019) for SFGs with different stellar masses (M_star = 10^9.6, 10^10.6, and 10^11.6 M_⊙ in yellow, orange, and red, respectively).