Post-revolution Cuba has been characterized by significant levels of emigration, which has led to a large and influential diaspora community. During the three decades after January 1959, more than one million Cubans of all social classes — constituting 10% of the total population — emigrated to the United States, a proportion that matches the extent of emigration to the U.S. from the Caribbean as a whole during that period. Prior to 13 January 2013, Cuban citizens could not travel abroad, leave or return to Cuba without first obtaining official permission along with applying for a government issued passport and travel visa, which was often denied. Those who left the country typically did so by sea, in small boats and fragile rafts. On 9 September 1994, the U.S. and Cuban governments agreed that the U.S. would grant at least 20,000 visas annually in exchange for Cuba's pledge to prevent further unlawful departures on boats. As of 2013 the top emigration destinations were the United States, Spain, Italy, Puerto Rico, and Mexico.