CO(3-2) luminosity, , plotted against FIR luminosity, L_FIR (left panel) and CO(1–0) luminosity, (right) for our targets. Also shown are values taken from Mao et al. (2010) and Narayanan et al. (2005), see text for more discussion. The dashed lines show a robust unweighted regression for against the two variables plotted along the x-axis, not including our data. Some galaxies with extreme values are labeled. The left panel suggests that CO emission traced by the ¹²CO(3–2) transition is deficient relative to L_FIR (like ¹²CO(1–0), see Hunt et al. 2015), but that ¹²CO(3–2) relative to ¹²CO(1–0) is roughly consistent, implying that the excitation conditions in these metal-poor galaxies are similar to those in the metal-rich galaxy samples taken from the literature.