condition mean min max ZT0-3 1.1892406666666666 0.766779 1.931625 ZT4-7 2.80611 2.80611 2.80611 ZT8-11 6.484875000000001 6.484875000000001 6.484875000000001 ZT12-15 8.6973875 7.276115 10.11866 ZT16-19 4.619915 4.619915 4.619915 ZT20-23 2.133155 2.133155 2.133155