condition mean min max ZT0-3 17.455466666666666 16.481450000000002 19.1821 ZT4-7 11.038924999999999 11.038924999999999 11.038924999999999 ZT8-11 17.04035 17.04035 17.04035 ZT12-15 25.269675 24.8168 25.72255 ZT16-19 25.7239 25.7239 25.7239 ZT20-23 24.049999999999997 24.049999999999997 24.049999999999997