The number of people who migrated to foreign countries surged by 41 percent between 2000 and 2015 to 244 million, a United Nations study has found.
By far, the United States is the country with the largest portion of the world's migrants: 47 million, or one-fifth of the total, which includes 20 million refugees.
Germany and Russia shared the No. 2 spot with about 12 million each, followed by Saudi Arabia, with 10 million, Britain, with 9 million, and the United Arab Emirates, with 8 million.
The vast majority of international migrants -- two-thirds of the total -- are in Europe or Asia. Europe is home to 76 million migrants, while Asia has 75 million.
Europe and Asia also contribute the most to international migration. About 43 percent of migrants, or 108 million, come from Asia, while 25 percent, or 62 million, are from Europe.
While migrants are younger on average than the citizens of countries that host them, they are not expected to ease the worldwide trend toward population aging.