condition mean min max ZT0-3 3.8949049999999996 3.6496899999999997 4.14012 ZT4-7 3.5626499999999997 3.5626499999999997 3.5626499999999997 ZT8-11 4.40837 4.40837 4.40837 ZT12-15 0 0 0 ZT16-19 5.83829 5.83829 5.83829 ZT20-23 5.07754 5.07754 5.07754