condition mean min max ZT0-3 1.4888050000000002 1.4888050000000002 1.4888050000000002 ZT4-7 0.32629450000000004 0.32629450000000004 0.32629450000000004 ZT8-11 0.3399892 0.3399892 0.3399892 ZT12-15 0.1079025 0.1079025 0.1079025 ZT16-19 0.473605 0.473605 0.473605 ZT20-23 1.950985 1.950985 1.950985