condition mean min max ZT0-3 28.54008333333333 24.7194 30.9075 ZT4-7 18.10275 18.10275 18.10275 ZT8-11 47.054249999999996 47.054249999999996 47.054249999999996 ZT12-15 63.908550000000005 59.072900000000004 68.7442 ZT16-19 40.266999999999996 40.266999999999996 40.266999999999996 ZT20-23 38.09525 38.09525 38.09525