condition mean min max ZT0-3 25.799999999999997 25.799999999999997 25.799999999999997 ZT4-7 3.7 3.7 3.7 ZT8-11 16.650000000000002 16.650000000000002 16.650000000000002 ZT12-15 27.2 27.2 27.2 ZT16-19 24.799999999999997 24.799999999999997 24.799999999999997 ZT20-23 8.649999999999999 8.649999999999999 8.649999999999999