condition mean min max ZT0-3 3.9 3.9 3.9 ZT4-7 3.0 3.0 3.0 ZT8-11 23.799999999999997 23.799999999999997 23.799999999999997 ZT12-15 8.45 8.45 8.45 ZT16-19 3.7 3.7 3.7 ZT20-23 3.3499999999999996 3.3499999999999996 3.3499999999999996