Top: CFE against mass of the MMC (M_MMC). Symbols are defined as in Figure 4. Bottom: distribution of the ratio between the mass of the MMC and the total mass contained in cores (excluding clumps with N_core=0 or 1), shown separately for quiescent (red histogram), star forming (blue), and UCHII regions (cyan). The dashed curves represent the corresponding cumulative distributions, with values referenced to the y-axis on the right side of the plot. The vertical dotted lines mark the median values for each subclass, using the same color scheme as the histograms.