Today is World Refugee Day, an annual observance created by the United Nations to memorate the strength, courage and perseverance of millions of refugees.” Here are five facts you should know about refugees and refugee policy in the United States.

1. The U.S. government defines “refugee” as any person who is outside any country of such person’s nationality or, in the case of a person having no nationality, is outside any country in which such person last habitually resided, and who is unable or unwilling to return to, and is unable or unwilling to avail himself or herself of the protection of, that country because of persecution or a well-founded fear of persecution on account of race, religion, nationality, membership in a particular social group, or political opinion.

2. Thefirst refugee legislation in the United Stateswas theDisplaced Persons Act of 1948, which brought 400,000 Eastern Europeans to the U.S. Other refugee-related legislation included theRefugee Relief Act of 1953(which brought in 214,000 refugees munism) and theFair Share Refugee Act of 1960(which mostly brought those still living in displaced persons camps after World War II). The U.S. government also used the Attorney General’shumanitarian parole authorityto bring refugees into the country, beginning in 1956 with Hungarian nationals and ending with hundreds of thousands of Indochinese refugees in the 1970s.

3. The number of refugees admitted into the U.S. each year is decided by the President. Before the beginning of each fiscal year, the President, in consultationwith Congress, establishes anoverall refugee admissions ceilingas well as regional allocations. So far in So far during the 2017 fiscal year, 45,732 people have been admitted. The total number of refugees authorized for admission in 2015—the last year for which official statistics are available—was 69,920. The largest regional allocation was from Burma (18,386), Iraq (12,676), Somalia (8,858), and the Democratic Republic of the Congo (7,876).

4. Since 1975, the U.S. has resettled more than3 million refugees, with nearly 77 percentbeing either Indochinese or citizens of the former Soviet Union. Since the enactment of the Refugee Act of 1980, annual admissions figures have ranged from a high of 207,116 in 1980, to a low of 27,100 in 2002. In 2013, theleading countries of nationalityfor refugee admissions were Iraq (28 percent), Burma (23 percent), Bhutan (13 percent), and Somalia (11 percent). Seventy-five percent of refugee admissions in 2013 were from these four countries. Other leading countries included Cuba (6.0 percent), Iran (3.7 percent), Democratic Republic of Congo (3.7 percent), and Sudan (3.1 percent).

5. TheOffice of Refugee Resettlement (ORR)is the federal government agency charged withproviding benefits and servicesto assist the resettlement and localintegration of refugee populations. Some of the ORR programs include Refugee CashAssistance and Refugee Medical Assistance (for up to 8 months); Refugee Social Services, such as job and language training (for up to 5 years); and temporary custody and care to panied refugee children. But according to a recent paper by the National Bureau of Economic Research, by the time refugees who entered the U.S. as adults have been here for 20 years, they will have paid, on average, $21,000 more in taxes to all levels of government than they received in benefits over that time span.