Remittances for the month of April totaled about $1.7 billion, 18.6 percent less than the $2.1 billion recorded in April 2008, Mexico's Central Bank said. After oil, remittances account for Mexico's largest source of income, and their decline is certain to further erode economic growth here. Experts cite several reasons for the drop in money sent home by the estimated 12 million Mexicans living in the United States, including recession in the U.S. and widening unemployment among migrant workers. In addition, tighter security at the nations' shared border has deterred some Mexicans from crossing northward in search of increasingly scarce jobs. Last year was the first time remittances declined overall for a 12-month period, after steady growth since authorities starting keeping records 13 years ago. The Mexican Finance Ministry recently announced that Mexico experienced its sharpest first-quarter shrinkage in economic activity since the mid-1990s, when the currency collapsed and the country plunged into depression as part of the 'Tequila Crisis.' And the downturn was registered even before Mexico endured the economic havoc wrought by a deadly outbreak of H1N1 flu. To contain the disease, the government closed schools, restaurants, some businesses and most cultural venues, crippling economic activity in many parts of the country. Mexico lost at least $2 billion as a result, the Finance Ministry says. Some losses are still being tabulated: Hardest hit was Mexico's third-largest source of income, tourism, after travelers canceled vacations, a number of countries suspended flights to Mexico and cruise ships skipped their Mexican ports of call. Hotel occupancy in late April and early May was down by as much as 90 percent in some areas, according to Tourism Minister Rodolfo Elizondo, who predicted losses for the year of up to $4 billion in this sector alone. On Monday, officials said tourism was beginning to pick up again, with hotels and restaurants reporting an increase in customers. Remittances, however, probably won't recover so quickly, experts said. Private sector analysts consulted by the central bank predicted a 5.8 percent contraction in the country's gross domestic product in 2009 and the loss of nearly 600,000 jobs. Mexico might have dodged one bullet: General Motors, which employs 13,000 people at four plants in Mexico, said its operations here will not be affected by its declaration of bankruptcy in the U.S. 