North Rhine-Westphalia, usually shortened to NRW, is the westernmost, the most populous, and the most economically powerful state of Germany. North Rhine-Westphalia has a population of approximately 18 million inhabitants, contributes about 22% to Germany's gross domestic product.The capital city is Düsseldorf, and the largest city is Cologne (Köln). The Ruhr Area falls entirely within North Rhine-Westphalia. From the 1960s, this region was strongly affected by a structural change away from coal mining and steel industry. Nevertheless, the Rhine-Ruhr  metropolitan region is the largest agglomeration of Germany and, of all states, North Rhine-Westphalia contributes the largest fraction to the national GDP.