condition mean min max ZT0-3 375.423887 375.423887 375.423887 ZT4-7 211.7841825 211.7841825 211.7841825 ZT8-11 208.37710399999997 208.37710399999997 208.37710399999997 ZT12-15 236.601495 236.601495 236.601495 ZT16-19 443.45995400000004 443.45995400000004 443.45995400000004 ZT20-23 495.0241355 495.0241355 495.0241355