condition mean min max ZT0-3 4.7993175 4.241255 5.35738 ZT4-7 2.70778 2.70778 2.70778 ZT8-11 3.2641999999999998 3.2641999999999998 3.2641999999999998 ZT12-15 0 0 0 ZT16-19 5.027464999999999 5.027464999999999 5.027464999999999 ZT20-23 4.50878 4.50878 4.50878