condition mean min max ZT0-3 15.060216666666667 12.36665 16.88285 ZT4-7 10.136140000000001 10.136140000000001 10.136140000000001 ZT8-11 11.37635 11.37635 11.37635 ZT12-15 18.637774999999998 18.287399999999998 18.988149999999997 ZT16-19 15.19425 15.19425 15.19425 ZT20-23 16.617449999999998 16.617449999999998 16.617449999999998