condition mean min max ZT0-3 5.91184 5.91184 5.91184 ZT4-7 3.722445 3.722445 3.722445 ZT8-11 4.4718 4.4718 4.4718 ZT12-15 4.8219899999999996 4.8219899999999996 4.8219899999999996 ZT16-19 5.2977799999999995 5.2977799999999995 5.2977799999999995 ZT20-23 5.87632 5.87632 5.87632