condition mean min max ZT0-3 92.341841 92.341841 92.341841 ZT4-7 143.109715 143.109715 143.109715 ZT8-11 126.533047 126.533047 126.533047 ZT12-15 113.568854 113.568854 113.568854 ZT16-19 42.2471735 42.2471735 42.2471735 ZT20-23 21.843105 21.843105 21.843105