condition mean min max ZT0-3 7.2112167005 7.02968731 7.392746091 ZT4-7 8.82924900575 8.740320584500001 8.918177427 ZT8-11 18.9640045875 14.813652075 23.1143571 ZT12-15 16.938737019999998 14.07381239 19.80366165 ZT16-19 16.24537897 14.94600708 17.54475086 ZT20-23 15.58095231 15.192152185 15.969752435