condition mean min max ZT0-3 3.1855332975 2.666351965 3.70471463 ZT4-7 2.9880735397500002 2.484044014 3.4921030655000003 ZT8-11 4.3020908662499995 3.8969947745000004 4.707186957999999 ZT12-15 6.029255643 4.6037227094999995 7.4547885765 ZT16-19 5.9648855235 5.3190725125 6.610698534499999 ZT20-23 8.758447327999999 8.09580707 9.421087586