condition mean min max ZT0-3 6.4908850000000005 6.4908850000000005 6.4908850000000005 ZT4-7 5.007765 5.007765 5.007765 ZT8-11 4.4287399999999995 4.4287399999999995 4.4287399999999995 ZT12-15 6.9195899999999995 6.9195899999999995 6.9195899999999995 ZT16-19 8.1618 8.1618 8.1618 ZT20-23 8.754655 8.754655 8.754655