Vertical profiles for CO isotopologues as extracted from the channel maps of each disk. The shaded region shows the dispersion of the data points, and the solid coloured line traces the average values within each radial bin. Note that Elias 2-27 and WaOph 6 were observed at a higher transition (J = 3−2) in some CO isotopologues. Solid grey lines show a constant z/r of 0.1, 0.3, and 0.5. Each row has a different vertical extent.