Box plot of distributions of bolometric luminosity-to-mass ratios for clumps associated with different masers. Except for class I maser data, the plotting data for H₂O, OH, and class II methanol masers at 6.7 and 12.2 GHz are from Fig. 7(A) in Ladeyschikov et al. (2022). The boxes filled in red, blue, light yellow, and green indicate the class I and II methanol masers, H₂O, and OH masers, respectively. Each box represents the interquartile range between the 25th and 75th percentiles, with a thick black line denoting the median value. The whiskers show the full range of the data.