condition mean min max ZT0-3 9.799999999999999 9.799999999999999 9.799999999999999 ZT4-7 18.6 18.6 18.6 ZT8-11 2.5 2.5 2.5 ZT12-15 6.0 6.0 6.0 ZT16-19 24.45 24.45 24.45 ZT20-23 43.7 43.7 43.7