condition mean min max ZT0-3 5.85 5.85 5.85 ZT4-7 1.4 1.4 1.4 ZT8-11 11.799999999999999 11.799999999999999 11.799999999999999 ZT12-15 15.5 15.5 15.5 ZT16-19 15.049999999999999 15.049999999999999 15.049999999999999 ZT20-23 29.5 29.5 29.5