Statistics of Lyα detection in LGRB host galaxy samples. Top panel: cumulative number of galaxies in the TOUGH (orange line), XHG (blue line), and merged samples (TOUGH+XHG, green) without overlapping GRBs as a function of Lyα luminosity detection threshold (3σ) of the spectra. The dashed lines represent the number of detected LAEs above the Lyα luminosity threshold in each sample. Bottom panel: fraction of detected LAEs for each sample as a function of Lyα luminosity threshold.