condition mean min max ZT0-3 1.5526784999999999 0.771415 2.9789505 ZT4-7 2.5129 2.5129 2.5129 ZT8-11 0.531455 0.531455 0.531455 ZT12-15 0.621786 0.189757 1.053815 ZT16-19 1.460065 1.460065 1.460065 ZT20-23 1.710295 1.710295 1.710295