condition mean min max ZT0-3 15.9347 15.9347 15.9347 ZT4-7 10.24673 10.24673 10.24673 ZT8-11 18.09915 18.09915 18.09915 ZT12-15 16.2921 16.2921 16.2921 ZT16-19 15.958300000000001 15.958300000000001 15.958300000000001 ZT20-23 16.23805 16.23805 16.23805