condition mean min max ZT0-3 1.099721 0.834877 1.3645649999999998 ZT4-7 1.2717075 1.2717075 1.2717075 ZT8-11 2.324455 2.324455 2.324455 ZT12-15 0 0 0 ZT16-19 2.3339749999999997 2.3339749999999997 2.3339749999999997 ZT20-23 1.5735700000000001 1.5735700000000001 1.5735700000000001