condition mean min max ZT0-3 1.8275133333333335 1.3026900000000001 2.18733 ZT4-7 1.507105 1.507105 1.507105 ZT8-11 2.28991 2.28991 2.28991 ZT12-15 3.6881775 3.687875 3.68848 ZT16-19 3.135865 3.135865 3.135865 ZT20-23 3.3178400000000003 3.3178400000000003 3.3178400000000003