condition mean min max ZT0-3 0.198661 0.16864200000000001 0.22868 ZT4-7 0.3163325 0.3163325 0.3163325 ZT8-11 0.2866355 0.2866355 0.2866355 ZT12-15 0 0 0 ZT16-19 0.7592095 0.7592095 0.7592095 ZT20-23 0.338716 0.338716 0.338716