condition mean min max ZT0-3 8.870269237833334 7.582970510333333 10.157567965333334 ZT4-7 9.294859819 8.901104227333333 9.688615410666667 ZT8-11 7.864076215833334 6.310889015666667 9.417263416 ZT12-15 7.429850790166667 5.865951034333333 8.993750546000001 ZT16-19 7.0115729255 6.820099922000001 7.203045929 ZT20-23 6.7128803285 5.3353630249999995 8.090397632