condition mean min max ZT0-3 18.891375 18.2708 19.51195 ZT4-7 24.33595 24.33595 24.33595 ZT8-11 21.424599999999998 21.424599999999998 21.424599999999998 ZT12-15 0 0 0 ZT16-19 25.75325 25.75325 25.75325 ZT20-23 22.870449999999998 22.870449999999998 22.870449999999998