condition mean min max ZT0-3 2.256998333333333 1.74797 3.0170649999999997 ZT4-7 1.3194659999999998 1.3194659999999998 1.3194659999999998 ZT8-11 1.56378 1.56378 1.56378 ZT12-15 2.7108825 2.38969 3.032075 ZT16-19 1.851305 1.851305 1.851305 ZT20-23 3.6285950000000002 3.6285950000000002 3.6285950000000002