condition mean min max ZT0-3 3.615925 2.8966149999999997 4.335235 ZT4-7 2.7450599999999996 2.7450599999999996 2.7450599999999996 ZT8-11 2.930945 2.930945 2.930945 ZT12-15 0 0 0 ZT16-19 2.31851 2.31851 2.31851 ZT20-23 2.142305 2.142305 2.142305