condition mean min max ZT0-3 18.777244 18.777244 18.777244 ZT4-7 15.703826 15.703826 15.703826 ZT8-11 14.3956695 14.3956695 14.3956695 ZT12-15 16.2127965 16.2127965 16.2127965 ZT16-19 14.197635 14.197635 14.197635 ZT20-23 14.298541499999999 14.298541499999999 14.298541499999999