condition mean min max ZT0-3 1.8785468333333333 0.7689155000000001 2.75472 ZT4-7 1.2607005 1.2607005 1.2607005 ZT8-11 2.326715 2.326715 2.326715 ZT12-15 2.9348475 2.531815 3.33788 ZT16-19 5.635475 5.635475 5.635475 ZT20-23 4.2870550000000005 4.2870550000000005 4.2870550000000005