condition mean min max ZT0-3 0.8000546107500001 0.195709605 1.4043996165000001 ZT4-7 5.10971613625 4.0214713095 6.197960963 ZT8-11 7.42166201975 7.035872748 7.8074512915 ZT12-15 8.9859664495 7.9185831685 10.053349730499999 ZT16-19 14.2204230565 10.074655258 18.366190855 ZT20-23 24.631117015 22.504027895 26.758206135000002