condition mean min max ZT0-3 2.12199 2.12199 2.12199 ZT4-7 1.67838 1.67838 1.67838 ZT8-11 1.2797749999999999 1.2797749999999999 1.2797749999999999 ZT12-15 2.053785 2.053785 2.053785 ZT16-19 2.90687 2.90687 2.90687 ZT20-23 2.84307 2.84307 2.84307