condition mean min max ZT0-3 0.3297636666666667 0.0 0.649745 ZT4-7 1.277355 1.277355 1.277355 ZT8-11 0.3342775 0.3342775 0.3342775 ZT12-15 0.27404275 0.1850905 0.362995 ZT16-19 0.47932700000000006 0.47932700000000006 0.47932700000000006 ZT20-23 0.358259 0.358259 0.358259