condition mean min max ZT0-3 34.06868333333333 31.923699999999997 36.20815 ZT4-7 28.365650000000002 28.365650000000002 28.365650000000002 ZT8-11 20.3966 20.3966 20.3966 ZT12-15 29.575825 28.23155 30.920099999999998 ZT16-19 24.657049999999998 24.657049999999998 24.657049999999998 ZT20-23 31.6269 31.6269 31.6269