condition mean min max ZT0-3 5.0442725 4.91245 5.176095 ZT4-7 3.6288149999999995 3.6288149999999995 3.6288149999999995 ZT8-11 6.388885 6.388885 6.388885 ZT12-15 0 0 0 ZT16-19 6.921615 6.921615 6.921615 ZT20-23 4.36915 4.36915 4.36915