condition mean min max ZT0-3 1.389386 1.363539 1.4152330000000002 ZT4-7 2.1397 2.1397 2.1397 ZT8-11 3.357765 3.357765 3.357765 ZT12-15 0 0 0 ZT16-19 3.9581399999999998 3.9581399999999998 3.9581399999999998 ZT20-23 2.864495 2.864495 2.864495