condition mean min max ZT0-3 7.24810960725 7.0360083155 7.460210899 ZT4-7 6.767477406166667 6.017441279 7.517513533333334 ZT8-11 11.3569057345 9.918331292 12.795480177 ZT12-15 10.2998621175 9.725105801 10.874618434 ZT16-19 7.682864061333333 7.011497565666667 8.354230557000001 ZT20-23 5.9834748895 5.459910873 6.507038906