condition mean min max ZT0-3 4.089673333333334 3.031625 5.0781600000000005 ZT4-7 2.7105699999999997 2.7105699999999997 2.7105699999999997 ZT8-11 1.87087 1.87087 1.87087 ZT12-15 3.4108525 3.36082 3.460885 ZT16-19 3.789735 3.789735 3.789735 ZT20-23 5.518605 5.518605 5.518605