condition mean min max ZT0-3 18.895631666666667 7.650895 25.9922 ZT4-7 4.73557 4.73557 4.73557 ZT8-11 5.87195 5.87195 5.87195 ZT12-15 10.2114775 7.4407049999999995 12.98225 ZT16-19 14.6226 14.6226 14.6226 ZT20-23 31.11235 31.11235 31.11235