condition mean min max ZT0-3 3.46542 3.46542 3.46542 ZT4-7 1.8888135 1.8888135 1.8888135 ZT8-11 0.987368 0.987368 0.987368 ZT12-15 1.0233615 1.0233615 1.0233615 ZT16-19 3.6452299999999997 3.6452299999999997 3.6452299999999997 ZT20-23 4.550015 4.550015 4.550015