condition mean min max ZT0-3 17.343700000000002 15.24665 19.44075 ZT4-7 14.836649999999999 14.836649999999999 14.836649999999999 ZT8-11 14.95965 14.95965 14.95965 ZT12-15 0 0 0 ZT16-19 21.119500000000002 21.119500000000002 21.119500000000002 ZT20-23 16.824350000000003 16.824350000000003 16.824350000000003