condition mean min max ZT0-3 8.093345 7.105935 9.465715 ZT4-7 2.663075 2.663075 2.663075 ZT8-11 0.733363 0.733363 0.733363 ZT12-15 2.9849125 2.6534950000000004 3.31633 ZT16-19 2.32206 2.32206 2.32206 ZT20-23 4.397005 4.397005 4.397005