Since the late 19th century, the United States has been the world's largest economy, ranking first in Gross Domestic Product (GDP), the world's largest importer and second only to China as the second largest exporter of goods. The United States contributes a quarter of global wealth and a third of global military spending. It has long been a strong country in the global economy, military, education, scientific research, aerospace, and medical technology, with the service sector predominant, a large manufacturing industry, and technology in a leading position worldwide. New York City is the most populous city in the United States and also a highly influential international financial center, rated as an Alpha++ global city by GaWC. The United States is a founding member of the United Nations, NATO, the Organization of American States, the International Monetary Fund, the World Bank, and the World Trade Organization, as well as a permanent member of the UN Security Council, with profound political and cultural influence on the world.