Correlation plots of column densities normalized to methanol in G135.27 MM1 compared to G31.41 (panel a) and WB89-789 (panel b). Oxygen-, nitrogen-, and nitrogen+oxygen-bearing molecules are marked in red, purple, and magenta, respectively. Dashed and dotted lines indicate deviations by factors of 100 and 10, respectively. The Pearson correlation coefficient (r) and P-value for each comparison are shown in the top-left corner of each panel.