Left panel: Lyα escape fraction as a function of redshift for the bright (gray diamonds) and faint (gray triangles) volume limited samples. Strong Lyα emitters with EW₀> 25 Å and EW₀> 55 Å are shown with cyan and magenta empty circles, respectively. Objects with formally negative equivalent width of Lyα, corresponding to negative Lyα luminosity, are set here to log [ f_esc(Lyα) ] = − 3. The big red and blue circles indicate the median escape fraction for the galaxies with EW₀ [ Lyα ] > 55 Å and EW₀ [ Lyα ] > 25 Å, respectively. The black (gray) arrows indicate the f_esc(Lyα) below which 80% of the bright (faint) objects lie. Right panel: Lyα escape fraction as a function of the E(B − V). The symbols are the same than in the left panel. The green dashed line shows the prediction by Verhamme et al. (2006).