condition mean min max ZT0-3 30.450000000000003 30.450000000000003 30.450000000000003 ZT4-7 3.2 3.2 3.2 ZT8-11 29.75 29.75 29.75 ZT12-15 23.799999999999997 23.799999999999997 23.799999999999997 ZT16-19 10.100000000000001 10.100000000000001 10.100000000000001 ZT20-23 23.0 23.0 23.0