condition mean min max ZT0-3 17.95 17.95 17.95 ZT4-7 3.3 3.3 3.3 ZT8-11 17.799999999999997 17.799999999999997 17.799999999999997 ZT12-15 3.3 3.3 3.3 ZT16-19 27.200000000000003 27.200000000000003 27.200000000000003 ZT20-23 5.6 5.6 5.6