condition mean min max ZT0-3 5.450145 4.1217500000000005 6.3546 ZT4-7 3.498495 3.498495 3.498495 ZT8-11 7.419745000000001 7.419745000000001 7.419745000000001 ZT12-15 7.498685 7.293335000000001 7.704034999999999 ZT16-19 6.688925 6.688925 6.688925 ZT20-23 4.83694 4.83694 4.83694