condition mean min max ZT0-3 6.28598 6.28598 6.28598 ZT4-7 5.75244 5.75244 5.75244 ZT8-11 3.3883599999999996 3.3883599999999996 3.3883599999999996 ZT12-15 4.5949100000000005 4.5949100000000005 4.5949100000000005 ZT16-19 7.495465 7.495465 7.495465 ZT20-23 6.26523 6.26523 6.26523