<P> Between 2000 and 2015, Asia added more international migrants than any other major area in the world, gaining 26 million . Europe added the second largest with about 20 million . In most parts of the world, migration occurs between countries that are located within the same major area . </P> <P> In 2015, the number of international migrants below the age of 20 reached 37 million, while 177 million are between the ages of 20 and 64 . International migrants living in Africa were the youngest, with a median age of 29, followed by Asia (35 years), and Latin America / Caribbean (36 years), while migrants were older in Northern America (42 years), Europe (43 years), and Oceania (44 years). </P> <P> Nearly half (43%) of all international migrants originate in Asia, and Europe was the birthplace of the second largest number of migrants (25%), followed by Latin America (15%). India has the largest diaspora in the world (16 million people), followed by Mexico (12 million) and Russia (11 million). </P> <P> A 2012 survey by Gallup found that given the opportunity, 640 million adults would migrate to another country, with 23% of these would - be immigrant choosing the United States as their desired future residence, while 7% of respondents, representing 45 million people, would choose the United Kingdom . The other top desired destination countries (those where an estimated 69 million or more adults would like to go) were Canada, France, Saudi Arabia, Australia, Germany and Spain . </P>

List 5 possible negative effects of immigration on cities