condition mean min max ZT0-3 2.95586 2.95586 2.95586 ZT4-7 3.463035 3.463035 3.463035 ZT8-11 1.904975 1.904975 1.904975 ZT12-15 3.7690349999999997 3.7690349999999997 3.7690349999999997 ZT16-19 3.25312 3.25312 3.25312 ZT20-23 2.4267849999999997 2.4267849999999997 2.4267849999999997