Detection rates of class II methanol masers versus the BGPS beam-averaged H₂ column density (left), and integrated flux density of the BGPS sources (right). For each BGPS property, the upper panel shows the histogram distributions of total sample sources (blank) and detected 6.7 GHz class II methanol maser sources (hatched), and the lower panel shows the corresponding detection rate of class II methanol maser in each statistical bin.