condition mean min max ZT0-3 17.655871 17.655871 17.655871 ZT4-7 19.015392499999997 19.015392499999997 19.015392499999997 ZT8-11 38.5878805 38.5878805 38.5878805 ZT12-15 50.322646 50.322646 50.322646 ZT16-19 51.017382 51.017382 51.017382 ZT20-23 28.2032515 28.2032515 28.2032515