condition mean min max ZT0-3 16.424983333333333 12.618500000000001 19.88385 ZT4-7 8.931765 8.931765 8.931765 ZT8-11 11.690850000000001 11.690850000000001 11.690850000000001 ZT12-15 23.691575 20.8301 26.55305 ZT16-19 20.95295 20.95295 20.95295 ZT20-23 19.53855 19.53855 19.53855