condition mean min max ZT0-3 1.9547400000000001 1.9547400000000001 1.9547400000000001 ZT4-7 3.462875 3.462875 3.462875 ZT8-11 1.5806650000000002 1.5806650000000002 1.5806650000000002 ZT12-15 1.7967149999999998 1.7967149999999998 1.7967149999999998 ZT16-19 2.797435 2.797435 2.797435 ZT20-23 2.6561950000000003 2.6561950000000003 2.6561950000000003