condition mean min max ZT0-3 11.146421666666667 10.817165 11.3619 ZT4-7 9.493939999999998 9.493939999999998 9.493939999999998 ZT8-11 19.55755 19.55755 19.55755 ZT12-15 21.74035 20.114199999999997 23.366500000000002 ZT16-19 13.8856 13.8856 13.8856 ZT20-23 10.475495 10.475495 10.475495