Spread in fractions in the four evolutionary stages for DCN/DNC and HCN/HNC for detections in both molecules only. If there are six or more detections within one stage, the blue box shows the 25−75% range and the crosses mark the other 50% of the data points. If there are fewer than six data points, only the individual data points are shown. The red solid line shows the median of the ratio of detections in both molecules.