condition mean min max ZT0-3 15.7199 12.0647 20.100900000000003 ZT4-7 14.03295 14.03295 14.03295 ZT8-11 6.535065 6.535065 6.535065 ZT12-15 8.3685975 7.3282799999999995 9.408915 ZT16-19 7.682855 7.682855 7.682855 ZT20-23 10.18846 10.18846 10.18846