In the case of any program operated by the Secretary or the Commodity Credit Corporation during the fiscal years 1991 through 1995, for the purpose of discouraging unfair trade practices, the Secretary shall establish as an objective to expend annually at least 25 percent of the total funds available (or 25 percent of the value of any commodities employed) for program activities involving the export sales of high-value agricultural commodities and value-added products of United States agricultural commodities.