Distribution of integrated intensity ratios of this survey’s 1 mm lines compared to published observations obtained with the IRAM 30 m telescope. The curve is a Gaussian fit to the histogram ruling out the “anomalous” ratios (≤ 0.5 or  ≥ 1.5). It can be noticed that the 12 “anomalous” ratios correspond to only 7 “anomalous spectra” among the 165 spectra observed in the 1 mm range.