Abundances of lukewarm (blue) and warm (red) COMs with respect to methanol from PDR regions to comets. Abundances in the Horsehead Nebula Photo-Dissociated Region (HN PDR) are taken from Guzman et al. (2014). Abundances in the TMC1 and L134N dark clouds are from Ohishi et al. (1992) and Gratier et al. (2016). Abundances in the B1-b, L1689B, and L1544 dense cores are taken from Öberg et al. (2010), Cernicharo et al. (2012), Bacmann et al. (2012), Bacmann & Faure (2016), and Vastel et al. (2014), Bizzocchi et al. (2014), Jiménez-Serra et al. (2016). Abundances in low-mass protostars are those derived in NGC 1333-IRAS2A by Taquet et al. (2015) for CH₂CO, CH₃OCHO, and CH₃OCH₃ and in IRAS 16293-2422-A by Jørgensen et al. (2016) for CH₃CHO, and CH₃OCHO. Abundances in high-mass hot cores are the mean values and the standard deviations of abundances derived from about 20 high-mass hot cores and compiled in Taquet et al. (2015). Abundances in the comet Hale-Bopp are those derived by Bockelee-Morvan et al. (2000).