condition mean min max ZT0-3 1.4784753333333334 0.772416 1.874685 ZT4-7 0.6277825 0.6277825 0.6277825 ZT8-11 2.216355 2.216355 2.216355 ZT12-15 2.2013625 1.7307800000000002 2.671945 ZT16-19 2.01696 2.01696 2.01696 ZT20-23 2.27531 2.27531 2.27531