condition mean min max ZT0-3 16.622429 16.622429 16.622429 ZT4-7 17.64721 17.64721 17.64721 ZT8-11 22.9292005 22.9292005 22.9292005 ZT12-15 15.26417 15.26417 15.26417 ZT16-19 16.6363105 16.6363105 16.6363105 ZT20-23 14.6852255 14.6852255 14.6852255