Top: histograms of the HCO⁺(2−1) integrated intensities in K km s⁻¹ (left) and HCO⁺(2−1)/HCN(2−1) integrated intensity ratios (right) of all the LOSs observed. LOSs with 0, 1, 2, and 3 YSOs are shown in green, orange, blue, and red, respectively. Bottom: characteristics of each of these distributions. The black box indicates the standard deviation, the colored line the mean value, and the dashed line indicates the minimum and maximum HCO⁺(2−1) intensity (left) or HCO⁺(2−1)/HCN(2−1) (right) for each distribution. The gray thick line indicates the standard deviation of the distribution when LOSs that have HCO⁺ detection and HCN upper limits are included.