condition mean min max ZT0-3 7.449999999999999 7.449999999999999 7.449999999999999 ZT4-7 9.3 9.3 9.3 ZT8-11 12.05 12.05 12.05 ZT12-15 38.2 38.2 38.2 ZT16-19 29.799999999999997 29.799999999999997 29.799999999999997 ZT20-23 30.950000000000003 30.950000000000003 30.950000000000003