condition mean min max ZT0-3 17.032704565 15.81389432 18.25151481 ZT4-7 12.91956578225 11.2286513395 14.610480225 ZT8-11 22.159880377500002 16.37680228 27.942958475000005 ZT12-15 23.29124073 21.763667925 24.818813534999997 ZT16-19 13.7086088725 12.64918221 14.768035535 ZT20-23 22.503708145 20.18552003 24.821896260000003