condition mean min max ZT0-3 3.1147850000000004 3.1147850000000004 3.1147850000000004 ZT4-7 1.61597 1.61597 1.61597 ZT8-11 1.99536 1.99536 1.99536 ZT12-15 2.41295 2.41295 2.41295 ZT16-19 3.9988200000000003 3.9988200000000003 3.9988200000000003 ZT20-23 3.3943849999999998 3.3943849999999998 3.3943849999999998