condition mean min max ZT0-3 0.909104 0.3941945 1.666355 ZT4-7 0.6529615 0.6529615 0.6529615 ZT8-11 0.0958995 0.0958995 0.0958995 ZT12-15 0.30120525 0.095965 0.5064455 ZT16-19 0.0 0.0 0.0 ZT20-23 0.70775 0.70775 0.70775