Number of sources versus the logarithm of their gas phase organic ratio over methanol with respect to the mean for O-bearing species. The solid filled histograms correspond to sources observed and analyzed here, the unfilled histograms correspond to sources from Bisschop et al. (2007) and Isokoski et al. (2013). The left panel presents the O-bearing species data, while the right panel focuses on the N-bearing molecules. HNCO abundances were derived assuming either hot compact emission or cold extended emission, since its origin does not seem to be consistent between sources.