condition mean min max ZT0-3 35.615586 35.615586 35.615586 ZT4-7 26.4828735 26.4828735 26.4828735 ZT8-11 21.6226195 21.6226195 21.6226195 ZT12-15 22.006785 22.006785 22.006785 ZT16-19 15.283696500000001 15.283696500000001 15.283696500000001 ZT20-23 15.396413 15.396413 15.396413