Comparison of global $L_{\text{HCN}}^{\prime }/L_{{\text{HCO}}^{\text{+}}}^{\prime }$ with (top, from left to right) AGN fraction, bolometric AGN luminosity, infrared luminosity, (bottom) star formation rate, IRAS 25 μm/60 μm flux density ratio, and the [N II]₁₂₂/[O III]₈₈ line ratio. In all panels, the numbers refer to IDs as defined in Table 1. Symbols are as in Fig. 1. Uncertainties are 1σ. For the [N II]₁₂₂/[O III]₈₈ line ratios, uncertainties are not available. Corresponding Spearman rank coefficients and p-values are listed in Table 5.