condition mean min max ZT0-3 1.807745 1.273525 2.097345 ZT4-7 1.214615 1.214615 1.214615 ZT8-11 2.3837800000000002 2.3837800000000002 2.3837800000000002 ZT12-15 3.3267425 3.0379500000000004 3.615535 ZT16-19 1.755475 1.755475 1.755475 ZT20-23 2.710755 2.710755 2.710755