In its latest study, the United Nations has reported a 41 percent rise in the number of migrants over the last 15 years. Of 244 million migrants registered last year, 20 million were refugees.
Two thirds of all international migrants were reported to be living in only 20 countries, with the largest number - about a fifth of the total - living in the United States. After the US, Germany, Russia and Saudi Arabia registered the largest number of migrants.
"The number of international migrants worldwide has continued to grow," UN Deputy Secretary-General Jan Eliasson said as he presented the key findings in New York on Tuesday. "Back in 2000, there were 173 million international migrants, in 2010 there were 222 million, and this past year in 2015, 244 million migrants."
The median age of migrants in 2015 was 39 years, with 15 percent of them aged less than 20 years old.
Eliasson said the figures also included 20 million refugees. Not included in the figures were around 40 million internally displaced people he added, describing them as "refugees inside a country."
Long term migration
The UN report did not take into account the motive for migration. Bela Hovy, from the UN's Department of Economic and Social Affairs Population Division, said the numbers included people who may have arrived at their new place of residence between ten and 40 years ago.
According to the report "Trends in International Migrant Stock: The 2015 Revision," 76 million international migrants live in Europe and 75 million in Asia. Women comprise half of all migrants.
"What I found particularly interesting is how important migration has been for population growth, which is sorely needed in certain parts of the world," Eliasson said. "In Europe, the size of the population would have fallen between 2000 to 2015, in the absence of positive net migration."
Most of the world's populations stay in their country of birth. Migrants made up just 3.3 percent of the global population in 2015, up from 2.8 percent 15 years ago.
jm/smm (AP, dpa)