condition mean min max ZT0-3 4.395146921 2.550613015 6.239680827 ZT4-7 3.1098549605 2.661730905 3.557979016 ZT8-11 4.36592528275 2.119211292 6.6126392735 ZT12-15 9.77309722825 8.4969277875 11.049266669 ZT16-19 9.51341527225 9.2929436865 9.733886858 ZT20-23 10.499931985 10.334426754999999 10.665437215