condition mean min max ZT0-3 11.444085 9.666055 12.8429 ZT4-7 9.46997 9.46997 9.46997 ZT8-11 15.460799999999999 15.460799999999999 15.460799999999999 ZT12-15 21.245675 19.5714 22.91995 ZT16-19 16.538899999999998 16.538899999999998 16.538899999999998 ZT20-23 13.71755 13.71755 13.71755