condition mean min max ZT0-3 4.865075 4.865075 4.865075 ZT4-7 2.835285 2.835285 2.835285 ZT8-11 3.71589 3.71589 3.71589 ZT12-15 3.883915 3.883915 3.883915 ZT16-19 7.988335 7.988335 7.988335 ZT20-23 6.102475 6.102475 6.102475