condition mean min max ZT0-3 19.046125 17.7421 20.35015 ZT4-7 18.313850000000002 18.313850000000002 18.313850000000002 ZT8-11 30.645 30.645 30.645 ZT12-15 0 0 0 ZT16-19 27.359 27.359 27.359 ZT20-23 23.58535 23.58535 23.58535