Line ratios for the nuclear region and inner-bar ends. Top: scatter plot showing the mean line ratios of the 7 hexagonal points for each molecule on the y-axis with respect to CO(2−1). For visualisation purpose we spaced the markers along the x-axis. The different shapes of the markers present the defined regions. The colourbar shows the normalised CO(2−1) integrated intensity to the mean CO(2−1) value. We plot the propagated errors in grey and find that they are very small. For the ratios we applied a signal-to-noise cut (see Sect. 5.1). Bottom: the relative differences of the line ratios with respect to the mean of the line ratios among the different regions (linear-scale).