condition mean min max ZT0-3 6.5865075 4.933005 8.24001 ZT4-7 7.134869999999999 7.134869999999999 7.134869999999999 ZT8-11 3.26342 3.26342 3.26342 ZT12-15 0 0 0 ZT16-19 5.2731449999999995 5.2731449999999995 5.2731449999999995 ZT20-23 7.38144 7.38144 7.38144