condition mean min max ZT0-3 17.028677107500002 14.261505565 19.79584865 ZT4-7 8.30970723875 7.2821850050000005 9.337229472499999 ZT8-11 10.850334446999998 9.134232528999998 12.566436365 ZT12-15 11.705139533250001 10.5458291865 12.86444988 ZT16-19 13.7375638325 12.65140272 14.823724944999999 ZT20-23 17.391691362499998 16.298844029999998 18.484538695