condition mean min max ZT0-3 2.20360599125 1.522991208 2.8842207745 ZT4-7 5.491757908 5.0925761045 5.8909397115 ZT8-11 3.7759038662499997 3.386783167 4.1650245654999996 ZT12-15 11.09716280875 7.7153393825 14.478986235 ZT16-19 17.252128775 16.65686306 17.84739449 ZT20-23 20.032781475 19.515246755 20.550316195