condition mean min max ZT0-3 19.5921 19.14725 20.036949999999997 ZT4-7 12.608899999999998 12.608899999999998 12.608899999999998 ZT8-11 16.242449999999998 16.242449999999998 16.242449999999998 ZT12-15 0 0 0 ZT16-19 15.481349999999999 15.481349999999999 15.481349999999999 ZT20-23 19.626849999999997 19.626849999999997 19.626849999999997