condition mean min max ZT0-3 1.9538883333333332 1.3208799999999998 2.308865 ZT4-7 0.5335285 0.5335285 0.5335285 ZT8-11 1.235535 1.235535 1.235535 ZT12-15 3.0378524999999996 2.966385 3.10932 ZT16-19 3.042765 3.042765 3.042765 ZT20-23 2.5422700000000003 2.5422700000000003 2.5422700000000003