Question: When did the country providing the most legal immigrants in 2013 out of all countries from the continent where the river of which the Tebicuary is a tributary can be found change to the US dollar?

full_context: Document 1: Currencies of Puerto Rico: The situado was discontinued during the 19th century, creating an economic crisis, as a result of Mexico gaining its independence from Spain. Salvador Meléndez Bruna, the colonial governor in office, ordered the issue of provincial banknotes, creating the Puerto Rican peso. However, printing of these banknotes ceased after 1815. During the following decades, foreign coins became the widespread currency. In the 1860s and 1870s, banknotes reemerged. On February 1, 1890, the Banco Español de Puerto Rico was inaugurated and began issuing banknotes. The bank designed four series and placed three in circulation under Spanish rule. In 1895, a Royal Decree ordered the production of provincial peso coins.
Document 2: New York City: Approximately 37% of the city's population is foreign born. In New York, no single country or region of origin dominates. The ten largest sources of foreign-born individuals in the city as of 2011 were the Dominican Republic, China, Mexico, Guyana, Jamaica, Ecuador, Haiti, India, Russia, and Trinidad and Tobago, while the Bangladeshi immigrant population has since become one of the fastest growing in the city, counting over 74,000 by 2013.
Document 3: Mexico City: On the other hand, Mexico City is also home to large communities of expatriates and immigrants, most notably from the rest of North America (U.S. and Canada), from South America (mainly from Argentina and Colombia, but also from Brazil, Chile, Uruguay and Venezuela), from Central America and the Caribbean (mainly from Cuba, Guatemala, El Salvador, Haiti and Honduras); from Europe (mainly from Spain, Germany and Switzerland, but also from Czech Republic, Hungary, France, Italy, Ireland, the Netherlands, Poland and Romania), from the Middle East (mainly from Egypt, Lebanon and Syria); and recently from Asia-Pacific (mainly from China and South Korea). Historically since the era of New Spain, many Filipinos settled in the city and have become integrated in Mexican society. While no official figures have been reported, population estimates of each of these communities are quite significant.
Document 4: Paraguay: Paraguay (; ; , ), officially the Republic of Paraguay (; ), is a country in South America. It is bordered by Argentina to the south and southwest, Brazil to the east and northeast, and Bolivia to the northwest. Although it is one of only two landlocked countries in South America (the other is Bolivia), the country has coasts, beaches and ports on the Paraguay and Paraná rivers that give exit to the Atlantic Ocean through the . Due to its central location in South America, it is sometimes referred to as "Corazón de Sudamérica" ("Heart of South America").
Document 5: New York City: Ecuador, Colombia, Guyana, Peru, and Brazil were the top source countries from South America for legal immigrants to the New York City region in 2013; the Dominican Republic, Jamaica, Haiti, and Trinidad and Tobago in the Caribbean; Egypt, Ghana, and Nigeria from Africa; and El Salvador, Honduras, and Guatemala in Central America. Amidst a resurgence of Puerto Rican migration to New York City, this population had increased to approximately 1.3 million in the metropolitan area as of 2013.
Document 6: Guaporé River: Guaporé River (Portuguese: Rio Guaporé) is a river in western Brazil and northeastern Bolivia. Its Bolivian name is Río Iténez. It is 1,530 km (950 mi) long; 970 km (600 mi) of the river forms the border between Brazil and Bolivia.
Document 7: Salvadoran colón: The colón was the currency of El Salvador between 1892 and 2001, until it was replaced by the U.S. Dollar. It was subdivided into 100 centavos and its ISO 4217 code was SVC. The plural is colones in Spanish and was named after Christopher Columbus, known as Cristóbal Colón in Spanish.
Document 8: São Lourenço River (Mato Grosso): The São Lourenço River is a tributary of the Paraguay River within the Pantanal, an alluvial plain that spans portions of Brazil, Bolivia and Paraguay.
Document 9: Currency of Ecuador: The US dollar became legal tender in Ecuador March 13, 2000, and sucre notes ceased being legal tender on September 11. Sucre notes remained exchangeable at Banco Central until March 30, 2001, at 25,000 sucres per dollar. Ecuador now only issues its own centavo coins.
Document 10: Guaíra, Paraná: Guaíra is a municipality in the state of Paraná in the Southern Region of Brazil. The population is 32,591 (2015 est.) in an area of 560 km². The elevation is 517 m. This place name comes from the Tupi language and means "place difficult to access". The city is served by Guaíra Airport.
Document 11: Paraguay River: The Paraguay River (Río Paraguay in Spanish, Rio Paraguai in Portuguese, Ysyry Paraguái in Guarani) is a major river in south-central South America, running through Brazil, Bolivia, Paraguay and Argentina. It flows about from its headwaters in the Brazilian state of Mato Grosso to its confluence with the Paraná River north of Corrientes and Resistencia.
Document 12: Bermejo River: The Bermejo River (Spanish, Río Bermejo) is a river in South America that flows from Bolivia to the Paraguay River in Argentina. The river is generally called Bermejo in spite of its different names along its way, but it also has its own Native American names; in Wichí it is called Teuco, and in Guaraní it is called Ypitá. In the plains of Argentina's Gran Chaco the Bermejo forms wetlands and splits into two branches. The southern branch is the bed of the old Bermejo River, now an intermittent stream called Río Bermejito. The northern branch is now the main stem of the Bermejo and is called the Teuco River ("Río Teuco"), Bermejo Nuevo, or simply the Bermejo River. The two branches rejoin at , near Villa Río Bermejito, forming the Lower Bermejo River.
Document 13: Tebicuary River: The Tebicuary River (Spanish: Río Tebicuary), a tributary of Paraguay River is a river in Paraguay. Located in the southwestern part of that country, it flows eastwards discharging to Paraguay River about 45 km south of Formosa and 30 km north of Pilar.
Document 14: Euro: The changeover period during which the former currencies' notes and coins were exchanged for those of the euro lasted about two months, until 28 February 2002. The official date on which the national currencies ceased to be legal tender varied from member state to member state. The earliest date was in Germany, where the mark officially ceased to be legal tender on 31 December 2001, though the exchange period lasted for two months more. Even after the old currencies ceased to be legal tender, they continued to be accepted by national central banks for periods ranging from several years to indefinitely (the latter for Austria, Germany, Ireland, Estonia and Latvia in banknotes and coins, and for Belgium, Luxembourg, Slovenia and Slovakia in banknotes only). The earliest coins to become non-convertible were the Portuguese escudos, which ceased to have monetary value after 31 December 2002, although banknotes remain exchangeable until 2022.
Document 15: Quiquibey River: The Quiquibey River is a river in the Pilón Lajas Biosphere Reserve and Communal Lands in the north of Bolivia. The Quiquibey River joins the Beni River south of Rurrenabaque (upstream and south of Beni's tributary the Tuichi River). The river is the border between the departments of Beni and La Paz.
ground_truth: March 13, 2000
sub_queries: What is Tebicuary River a tributary of? Answer: Paraguay River
Which continent is Paraguay River on? Answer: South America
Of all the countries in South America , which provided the most legal immigrants in 2013? Answer: Ecuador
when did Ecuador change to the us dollar Answer: March 13, 2000