condition mean min max ZT0-3 8.532886361000001 7.981403616000001 9.084369106 ZT4-7 9.771444117749999 8.2319820305 11.310906204999998 ZT8-11 15.702431729999999 13.842877529999999 17.56198593 ZT12-15 11.062103603250002 9.857734979500002 12.266472227000001 ZT16-19 4.96358833475 4.870461951499999 5.056714718 ZT20-23 6.1028933717500005 5.254990830500001 6.950795913