In the mid-1990s, government approval of some GMO crops in the United States precipitated public concern in Europe and led to a dramatic decrease in American exports to Europe. "Prior to 1997, corn exports to Europe represented about 4% of total US corn exports, generating about $300 million in sales ... For example, before 1997, the U.S. sold about 1.75 million tons of corn annually to Spain and Portugal ... But in the 1998–99 crop year, Spain bought less than a tenth of the previous year's amount and Portugal bought none at all."