condition mean min max ZT0-3 1.6426283333333334 0.0 4.193345 ZT4-7 4.18641 4.18641 4.18641 ZT8-11 6.8036650000000005 6.8036650000000005 6.8036650000000005 ZT12-15 5.8218974999999995 5.6577649999999995 5.9860299999999995 ZT16-19 1.22716 1.22716 1.22716 ZT20-23 2.44478 2.44478 2.44478