condition mean min max ZT0-3 0.689992 0.5437555000000001 0.8362285 ZT4-7 0.3277495 0.3277495 0.3277495 ZT8-11 1.33101 1.33101 1.33101 ZT12-15 0 0 0 ZT16-19 1.24025 1.24025 1.24025 ZT20-23 1.0730885 1.0730885 1.0730885