condition mean min max ZT0-3 2.1614325 1.77385 2.549015 ZT4-7 3.073805 3.073805 3.073805 ZT8-11 0.7613255 0.7613255 0.7613255 ZT12-15 0 0 0 ZT16-19 0.2667035 0.2667035 0.2667035 ZT20-23 0.16054000000000002 0.16054000000000002 0.16054000000000002