condition mean min max ZT0-3 2.8954766666666667 0.0 8.68643 ZT4-7 1.69254 1.69254 1.69254 ZT8-11 1.720295 1.720295 1.720295 ZT12-15 8.9042575 6.9205000000000005 10.888015 ZT16-19 8.126195 8.126195 8.126195 ZT20-23 3.6804249999999996 3.6804249999999996 3.6804249999999996