condition mean min max ZT0-3 14.1831 12.76675 15.59945 ZT4-7 19.157899999999998 19.157899999999998 19.157899999999998 ZT8-11 21.1597 21.1597 21.1597 ZT12-15 0 0 0 ZT16-19 22.031100000000002 22.031100000000002 22.031100000000002 ZT20-23 18.9431 18.9431 18.9431