condition mean min max ZT0-3 23.218733333333333 15.621849999999998 28.40515 ZT4-7 17.479 17.479 17.479 ZT8-11 5.28514 5.28514 5.28514 ZT12-15 9.409385 8.112825 10.705945 ZT16-19 8.548855 8.548855 8.548855 ZT20-23 8.20763 8.20763 8.20763