condition mean min max ZT0-3 3.186635 0.0 5.0271799999999995 ZT4-7 0.474621 0.474621 0.474621 ZT8-11 2.456915 2.456915 2.456915 ZT12-15 4.154059999999999 2.564305 5.743815 ZT16-19 5.2247 5.2247 5.2247 ZT20-23 5.89361 5.89361 5.89361