condition mean min max ZT0-3 2.534325 2.28019 2.7884599999999997 ZT4-7 1.2183785 1.2183785 1.2183785 ZT8-11 2.801645 2.801645 2.801645 ZT12-15 0 0 0 ZT16-19 3.69444 3.69444 3.69444 ZT20-23 2.5166 2.5166 2.5166