condition mean min max ZT0-3 1.8032249999999999 1.278775 2.3982099999999997 ZT4-7 1.2696 1.2696 1.2696 ZT8-11 1.3803200000000002 1.3803200000000002 1.3803200000000002 ZT12-15 1.6118299999999999 1.60849 1.61517 ZT16-19 2.01389 2.01389 2.01389 ZT20-23 2.8847199999999997 2.8847199999999997 2.8847199999999997