condition mean min max ZT0-3 1.8698074999999998 1.860525 1.87909 ZT4-7 2.569905 2.569905 2.569905 ZT8-11 3.92861 3.92861 3.92861 ZT12-15 0 0 0 ZT16-19 3.887375 3.887375 3.887375 ZT20-23 2.465525 2.465525 2.465525