condition mean min max ZT0-3 1.829463 0.850976 2.80795 ZT4-7 2.635775 2.635775 2.635775 ZT8-11 0.5479015 0.5479015 0.5479015 ZT12-15 0 0 0 ZT16-19 0.717658 0.717658 0.717658 ZT20-23 2.22446 2.22446 2.22446