U.S. agricultural exports will remain historically high over much of the next decade, the U.S. Department of Agriculture (USDA) said on Thursday. "World economic growth, particularly sustained relatively high growth in developing countries, provides a foundation for increases in global food demand, trade, and U.S. agricultural exports," the USDA said, with the expectation that the global economy will grow at an annual average rate of about 3.2 percent over the next decade. Continued global biofuel demand and a weak U.S. dollar also contribute to rising commodity prices and gains in U.S. export values beyond 2016, according to the annual long-term projections report published by the USDA's Chief Economist Office. While the value of U.S. agricultural exports will decline slightly in the next two years, it is projected to grow again over the rest of the decade and surpass the 2013 record, the report said. High commodity prices pushed the value of U.S. agricultural exports to high levels in the past several years, including a record 141 billion U.S. dollars in 2013, it said. With prices for many crops projected to fall in the next two years, the agency estimated that agricultural export values will decline to 131.9 billion dollars in 2016, and then bounce back to 142 billion dollars in 2018 and continue to rise to 172.4 billion dollars by 2023, based on strong overseas demand.