condition mean min max ZT0-3 4.50887 3.4458800000000003 5.192740000000001 ZT4-7 1.253986 1.253986 1.253986 ZT8-11 3.4118399999999998 3.4118399999999998 3.4118399999999998 ZT12-15 3.648765 3.17065 4.12688 ZT16-19 2.168485 2.168485 2.168485 ZT20-23 4.340845 4.340845 4.340845