condition mean min max ZT0-3 14.571729999999999 7.4930900000000005 18.1928 ZT4-7 8.0992 8.0992 8.0992 ZT8-11 6.0357199999999995 6.0357199999999995 6.0357199999999995 ZT12-15 6.912515 6.723165 7.101865 ZT16-19 8.83437 8.83437 8.83437 ZT20-23 15.412400000000002 15.412400000000002 15.412400000000002