condition mean min max ZT0-3 240.242569 240.242569 240.242569 ZT4-7 265.874839 265.874839 265.874839 ZT8-11 275.1933385 275.1933385 275.1933385 ZT12-15 294.974102 294.974102 294.974102 ZT16-19 241.56973499999998 241.56973499999998 241.56973499999998 ZT20-23 231.35700450000002 231.35700450000002 231.35700450000002