Relation between the CO and the far-infrared luminosity integrated between 40 and 400 μm. The number of density of SIDES galaxies is coded using a gray scale. The best-fit observed relations of Greve et al. (2014, local and high-z (U)LIRGs), Liu et al. (2015, low-z sample), and Kamenetzky et al. (2016, low-z sample) are represented by a solid red, a dotted green, and a dashed blue line, respectively. These relations are plotted only in the luminosity range in which they were measured. It should be noted that the Liu et al. (2015) study does not include the three lowest rotationnal transitions of CO.