condition mean min max ZT0-3 0.177426 0.177426 0.177426 ZT4-7 0.0 0.0 0.0 ZT8-11 0.4226215 0.4226215 0.4226215 ZT12-15 0.5121915 0.5121915 0.5121915 ZT16-19 0.543343 0.543343 0.543343 ZT20-23 0.358853 0.358853 0.358853