condition mean min max ZT0-3 1.6039466666666666 1.1120450000000002 2.28205 ZT4-7 1.82043 1.82043 1.82043 ZT8-11 2.45545 2.45545 2.45545 ZT12-15 4.07932 3.49729 4.6613500000000005 ZT16-19 2.927015 2.927015 2.927015 ZT20-23 2.854045 2.854045 2.854045