condition mean min max ZT0-3 32.228725 29.904249999999998 34.5532 ZT4-7 21.268949999999997 21.268949999999997 21.268949999999997 ZT8-11 18.82615 18.82615 18.82615 ZT12-15 0 0 0 ZT16-19 27.1234 27.1234 27.1234 ZT20-23 28.161299999999997 28.161299999999997 28.161299999999997