condition mean min max ZT0-3 3.8170466666666663 3.17048 4.148899999999999 ZT4-7 3.2452300000000003 3.2452300000000003 3.2452300000000003 ZT8-11 2.01705 2.01705 2.01705 ZT12-15 2.859425 2.79138 2.92747 ZT16-19 1.80178 1.80178 1.80178 ZT20-23 3.120045 3.120045 3.120045