condition mean min max ZT0-3 20.884886 20.884886 20.884886 ZT4-7 27.8696805 27.8696805 27.8696805 ZT8-11 31.867485 31.867485 31.867485 ZT12-15 30.3944575 30.3944575 30.3944575 ZT16-19 58.51608 58.51608 58.51608 ZT20-23 36.06363 36.06363 36.06363