condition mean min max ZT0-3 5.9045266666666665 4.6373750000000005 8.21626 ZT4-7 4.31684 4.31684 4.31684 ZT8-11 3.02978 3.02978 3.02978 ZT12-15 4.6799349999999995 4.269304999999999 5.090565 ZT16-19 5.93604 5.93604 5.93604 ZT20-23 5.282425 5.282425 5.282425