condition mean min max ZT0-3 1.6234781692500002 1.041345812 2.2056105265 ZT4-7 3.6454100232499997 2.5190233485 4.771796697999999 ZT8-11 6.709012628750001 5.069926711000001 8.348098546500001 ZT12-15 11.959069046749999 10.893827645 13.0243104485 ZT16-19 10.63835150175 10.300291723499999 10.97641128 ZT20-23 12.367743459749999 10.148132689499999 14.587354229999999