Line luminosity of the CO (4–3) (upper panels), CO (6–5) (middle panels) and CO (7–6) emission (bottom panels) versus the bolometric luminosity (left panels), the mass of the clumps (middle panels) and the L∕M ratio (right panels) of the TOP100 sources. The median values for each class are shown as open diamonds and their error bars correspond to the absolute deviation of the data from their median value. Points having an upward arrow indicate a self-absorption feature in the spectrum convolved to 13.′′ 4 and correspond to a lower limit. The typical error bars are shown at the bottom right side of the plots. The black solid line is the best fit, the light grey shaded area indicates the 68% uncertainty, and the dashed lines show the intrinsic scatter (ϵ) of the relation.