condition mean min max ZT0-3 2.0732233333333334 1.7370299999999999 2.59863 ZT4-7 2.9818949999999997 2.9818949999999997 2.9818949999999997 ZT8-11 3.01918 3.01918 3.01918 ZT12-15 7.558377500000001 7.36948 7.747275 ZT16-19 4.646125 4.646125 4.646125 ZT20-23 3.463445 3.463445 3.463445