Over the last three decades, remittances ("remesas") from Dominicans living abroad, mainly in the United States, have become increasingly important to the economy. From 1990 to 2000, the Dominican population of the U.S. doubled in size, from 520,121 in 1990 to 1,041,910, two-thirds of whom were born in the Dominican Republic itself. More than half of all Dominican Americans live in New York City, with the largest concentration in the neighborhood of Washington Heights in northern Manhattan. Over the past decade, the Dominican Republic has become the largest source of immigration to New York City, and today the metropolitan area of New York has a larger Dominican population than any city except Santo Domingo. Dominican communities have also developed in New Jersey (particularly Paterson), Miami, Boston, Philadelphia, Providence, Rhode Island, and Lawrence, Massachusetts. In addition, tens of thousands of Dominicans and their descendants live in Puerto Rico. Many Dominicans arrive in Puerto Rico illegally by sea across the Mona Passage, some staying and some moving on to the mainland U.S. (See Dominican immigration to Puerto Rico.) Dominicans living abroad sent an estimated $3 billion in remittances to relatives at home, in 2006. In 1997, a new law took effect, allowing Dominicans living abroad to retain their citizenship and vote in presidential elections. President Fernández, who grew up in New York, was the principal beneficiary of this law.