condition mean min max ZT0-3 7.67861 7.36913 7.985715 ZT4-7 6.70655 6.70655 6.70655 ZT8-11 6.609715 6.609715 6.609715 ZT12-15 14.53445 14.471499999999999 14.5974 ZT16-19 8.821875 8.821875 8.821875 ZT20-23 8.23697 8.23697 8.23697