Trends between different nebula properties and the escape fraction. Shown are the age and mass of the stellar associations, the reddening E(B − V)_Balmer, the ionisation parameter log q, the local metallicity offset ∆(O/H) of the H II region, and the luminosity L(H α). The last row shows the global escape fraction (see Sect. 3.4) versus the fraction of DIG emission, the global escape fraction versus the average metallicity of the galaxy, and the escape fraction for different environments. The black lines represent the median values in each bin and the gray shaded areas indicate the 68 and 98 percentiles.