condition mean min max ZT0-3 2.603845 1.239195 3.576635 ZT4-7 1.1919335 1.1919335 1.1919335 ZT8-11 1.15184 1.15184 1.15184 ZT12-15 2.8398125 2.03031 3.6493149999999996 ZT16-19 3.789495 3.789495 3.789495 ZT20-23 5.013415 5.013415 5.013415