condition mean min max ZT0-3 17.2259035625 15.912722905 18.53908422 ZT4-7 11.9151073255 10.821085286 13.009129365 ZT8-11 13.85890143 12.020888685 15.696914175 ZT12-15 16.6226934275 15.40936164 17.836025215 ZT16-19 22.68014598 18.663449005 26.696842955 ZT20-23 38.45910473 34.896186895 42.022022565