condition mean min max ZT0-3 1.7860646666666666 0.888849 2.3922049999999997 ZT4-7 3.596615 3.596615 3.596615 ZT8-11 2.3439449999999997 2.3439449999999997 2.3439449999999997 ZT12-15 1.70329 1.603015 1.8035649999999999 ZT16-19 0.82635 0.82635 0.82635 ZT20-23 1.663075 1.663075 1.663075