The economy of the United States has undergone many changes over the past fifty years. One of the main characteristics of the early post-World War II era was the flourishing of the U.S. manufacturing industry. However, since the late 1970s, the most notable trends have been the rise of the service sector and the relative decline of the manufacturing and agricultural sectors. During the roughly twenty year period from 1977-98, the service sector, which includes service industries and the finance, insurance, and real estate industry, was the largest contributors to growth in real GDP (gross domestic product). From 1992 to 1998, the service sector increased from 61.2 percent to 64.7 percent of GDP. By contrast, the primary sector, which includes agriculture, forestry, and fishing, and the secondary sector, which includes such goods-producing industries as mining, construction, and manufacturing—decreased from 24.0 percent to 23.3 percent. Click on CHARTS, below for additional information on industries in the United States.