condition mean min max ZT0-3 1.455389 1.221157 1.6551300000000002 ZT4-7 0.768706 0.768706 0.768706 ZT8-11 0.346468 0.346468 0.346468 ZT12-15 1.02265925 0.6130335 1.432285 ZT16-19 2.05485 2.05485 2.05485 ZT20-23 2.41168 2.41168 2.41168