condition mean min max ZT0-3 11.926525 11.681799999999999 12.17125 ZT4-7 11.5347 11.5347 11.5347 ZT8-11 15.109449999999999 15.109449999999999 15.109449999999999 ZT12-15 0 0 0 ZT16-19 17.664749999999998 17.664749999999998 17.664749999999998 ZT20-23 17.08325 17.08325 17.08325