XLFs of LMXBs in galaxies with high and low S_N (see text for details) in cumulative (upper panel) and differential (lower panel) forms. The data for high-S_N galaxies (red in the color version of the plot) is marked by squares in the lower panel and is surrounded by the shaded area showing the 1σ Poissonian uncertainty in the upper panel. Statistical uncertainty for low-S_N galaxies has comparable amplitude.