condition mean min max ZT0-3 14.851541735 13.83628246 15.86680101 ZT4-7 10.623253089750001 9.4892322495 11.75727393 ZT8-11 9.573154937750001 9.0338308145 10.112479061 ZT12-15 5.617739770749999 5.2002259104999995 6.035253631 ZT16-19 8.713171693 6.0130821055000006 11.413261280499999 ZT20-23 16.9727179525 15.372645949999999 18.572789954999998