condition mean min max ZT0-3 5.114885 5.114885 5.114885 ZT4-7 3.417635 3.417635 3.417635 ZT8-11 4.843310000000001 4.843310000000001 4.843310000000001 ZT12-15 4.793279999999999 4.793279999999999 4.793279999999999 ZT16-19 7.614565000000001 7.614565000000001 7.614565000000001 ZT20-23 6.344345000000001 6.344345000000001 6.344345000000001