condition mean min max ZT0-3 3.1453325000000003 2.64629 3.644375 ZT4-7 1.605065 1.605065 1.605065 ZT8-11 1.16792 1.16792 1.16792 ZT12-15 0 0 0 ZT16-19 2.675925 2.675925 2.675925 ZT20-23 2.783465 2.783465 2.783465