condition mean min max ZT0-3 187.188797 187.188797 187.188797 ZT4-7 213.65463549999998 213.65463549999998 213.65463549999998 ZT8-11 272.775295 272.775295 272.775295 ZT12-15 222.0258335 222.0258335 222.0258335 ZT16-19 353.2268745 353.2268745 353.2268745 ZT20-23 304.78920899999997 304.78920899999997 304.78920899999997