condition mean min max ZT0-3 8.300998333333334 6.0465800000000005 10.355295 ZT4-7 4.16132 4.16132 4.16132 ZT8-11 7.3674599999999995 7.3674599999999995 7.3674599999999995 ZT12-15 17.209149999999998 17.0922 17.326099999999997 ZT16-19 17.067999999999998 17.067999999999998 17.067999999999998 ZT20-23 17.56315 17.56315 17.56315