condition mean min max ZT0-3 4.440754206499999 4.389127643 4.49238077 ZT4-7 3.50922279 3.273952744 3.744492836 ZT8-11 3.432246796 3.1904908924999997 3.6740026995 ZT12-15 5.290309210249999 3.6333015354999993 6.947316885 ZT16-19 3.5047757092500005 2.7468083295000003 4.262743089000001 ZT20-23 7.40137869825 6.242135941999999 8.560621454500001