Costa Rica's basically stable economy depends on tourism, agriculture, and electronics exports. Poverty has remained around 20% for nearly 20 years, and the strong social safety net that had been put into place by the government has eroded due to increased financial constraints on government expenditures. Immigration from Nicaragua has increasingly become a concern for the government. The estimated 300,000-500,000 Nicaraguans estimated to be in Costa Rica legally and illegally are an important source of (mostly unskilled) labor, but also place heavy demands on the social welfare system. Foreign investors remain attracted by the country's political stability and high education levels, as well as the fiscal incentives offered in the free-trade zones. Exports have become more diversified in the past 10 years due to the growth of the high-tech manufacturing sector, which is dominated by the microprocessor industry. Tourism continues to bring in foreign exchange, as Costa Rica's impressive biodiversity makes it a key destination for ecotourism. The government continues to grapple with its large internal and external deficits and sizable internal debt. Reducing inflation remains a difficult problem because of rising import prices, labor market rigidities, and fiscal deficits. Tax and public expenditure reforms will be necessary to close the budget gap. In October 2007, a national referendum voted in favor of the US-Central American Free Trade Agreement (CAFTA). Current Exchange Rate for Costa Rica.