condition mean min max ZT0-3 3.66486 3.66486 3.66486 ZT4-7 2.245785 2.245785 2.245785 ZT8-11 2.69782 2.69782 2.69782 ZT12-15 4.2762199999999995 4.2762199999999995 4.2762199999999995 ZT16-19 4.282915 4.282915 4.282915 ZT20-23 3.356135 3.356135 3.356135