condition mean min max ZT0-3 5.75837415 2.5406751169999997 8.976073183 ZT4-7 5.9257250845 5.440437198 6.411012971 ZT8-11 4.22062510875 4.0267625755 4.414487642 ZT12-15 1.42916742275 0.367806922 2.4905279234999997 ZT16-19 0.5218194875 0.398750275 0.6448887 ZT20-23 1.1192719975 1.1060934635000002 1.1324505315