Fraction of double-peaked LAEs plotted against the logarithmic Lyα luminosity and the redshift. Left panel: Fraction of double-peaked LAEs plotted against the logarithmic Lyα luminosity. The unbiased sample U has been divided into four luminosity bins with the same number of objects (51 or 52). The fraction of double-peaks has been derived in each bin. The results are positioned at the median Lyα luminosity of each bin. The horizontal black line at the top of the figure shows the size of each Lyα luminosity bin. Right panel: Fraction of double-peaked LAEs plotted against the redshift. The unbiased sample U has been divided into eight redshift bins with the same number of objects (25 or 26). The fraction of double-peaks has been derived in each bin. The results are positioned at the median redshift of each bin. The black stars surrounded in red represent the mean Lyα luminosity of each bin. The black dots represents the total fraction of double-peaks (N^UDP_I/N^U). The UDP_I is composed of GOLD and SILVER double-peaks. The yellow dots show the fraction of GOLD double-peaks (N^UDP_I GOLD/N^U) among U. The fraction of SILVER double-peaks (N^{UDP_I SILVER}/N^U) is represented by the grey dots.