condition mean min max ZT0-3 5.43486147575 2.558204125 8.3115188265 ZT4-7 14.608657815 13.278750025 15.938565605 ZT8-11 20.31199389 18.89151867 21.73246911 ZT12-15 21.3928901525 20.07613483 22.709645475000002 ZT16-19 20.507995815 19.03347896 21.98251267 ZT20-23 17.7623662375 17.56987518 17.954857295