The growth of foreign trade was especially significant for Germany, which by the middle of the nineteenth century was among the world’s three leading exporters. The German export trade at the time was mostly in food and raw materials. As worldwide economic connections grew and Germany itself developed from an agricultural into an industrial nation, world trade became increasingly important as an agent of German prosperity. Between 1850 and 1913 German foreign trade increased on the average of 4% annually, even faster than overall economic production. As a result, Germany’s share in the volume of world trade had reached 13% in 1913, while the export quota of the German Reich amounted to 17.5% of total industrial production.
That is from Wilfried Feldenkirchen, Werner von Siemens: Inventor and International Entrepreneur.