condition mean min max ZT0-3 814.126902 814.126902 814.126902 ZT4-7 434.39363749999995 434.39363749999995 434.39363749999995 ZT8-11 369.909071 369.909071 369.909071 ZT12-15 425.6612205 425.6612205 425.6612205 ZT16-19 328.95306200000005 328.95306200000005 328.95306200000005 ZT20-23 276.2912425 276.2912425 276.2912425