condition mean min max ZT0-3 27.5922 27.5922 27.5922 ZT4-7 24.1904 24.1904 24.1904 ZT8-11 16.26335 16.26335 16.26335 ZT12-15 17.3889 17.3889 17.3889 ZT16-19 24.579749999999997 24.579749999999997 24.579749999999997 ZT20-23 26.4503 26.4503 26.4503