condition mean min max ZT0-3 3.6500000000000004 3.6500000000000004 3.6500000000000004 ZT4-7 2.0 2.0 2.0 ZT8-11 15.799999999999999 15.799999999999999 15.799999999999999 ZT12-15 4.95 4.95 4.95 ZT16-19 4.800000000000001 4.800000000000001 4.800000000000001 ZT20-23 9.2 9.2 9.2