L_IR vs. L′_{[CI](1 − 0)} (panel a), L′_{CO(1 − 0)} (panel b) luminosities, L′_{[CI](1 − 0)}/L′_{CO(1 − 0)} ratio against redshift (panel c), and L′_{[CI](1 − 0)}/L′_{CO(1 − 0)} ratio against L_IR (panel d). The secondary y-axis represents the SFR and the secondary x-axis the total molecular masses computed using the corresponding tracer. We include the best fit using the Levenberg–Marquardt algorithm of the lmfit package (red dashed line), and the Bayesian approach to linear regression using the linmix package (solid black line). In panel (b) we include the relations presented in Sargent et al. (2014) for main-sequence galaxies (thick black dashed line), and starburst galaxies (dash-dotted line). In panels (a) and (b), the relations derived in Montoya Arroyave et al. (2023) for CO(1–0) and [C I](1–0) line detections are presented (magenta dashed lines). Panels (c) and (d) include the lmfit and linmix method fits, with solid red and dashed black lines, respectively. In panel (d), the black dash-dotted line presents the mean L′_{[CI](1 − 0)}/L′_{CO(1 − 0)} value and the scatter (gray shaded area) derived by Gerin & Phillips (2000).