Establishing how many people in any given year move from one country to live in another, either temporarily or permanently, is extremely difficult. However, in 2015 it was estimated that worldwide, over 244 million people were living in a country outside their country of origin. Yet these are not annual migration figures because many of these people are likely to have been living in their adopted country for years. Because it is so difficult to make these calculations on an annual basis, what often happens is that the growth rates of migration are calculated instead. This gives a good idea of how many people are mobile and the routes this mobility takes. For example, the 244 million figure means that by 2015, 3.3% of the world population were living outside of their country of origin. In 2013, this figure was 3.2% and in 2000 it was 2.8%. Making calculations by percentages of the current population, rather than using actual population figures, means that the result derived at gives a more accurate reflection of the proportion of people who are on the move, rather than being part of a number which is rising incrementally. The majority of the immigrants live in developed regions such as Europe, Asia and North America and they move due to social or economic reasons rather than being refugees or migrating illegally.

According to U.N data, migrants formed 2.8 percent of the world population in the year 2000. It rose to 3.3 percent in 2015. The number of migrants living worldwide was 244 million in 2015, 20 million of which were refugees. The top three regions of the world that migrants were present in were Europe, Asia and North America. In terms of countries, two-thirds of the total number of migrants lived in 20 countries with the U.S. leading the list followed by Germany and the Russian Federation.

World Bank Data of 2012 shows that India had 2.6 million people who had migrated out with Bangladesh reporting 2.5 million people who were living outside. The number of migrants out of these countries in 1962 was 85,000 and 142,000 respectively.

About 1.7 million Chinese were living outside of their country in 2012 rising from 1.1 million Chinese in 1962. The number of people who had migrated out of Pakistan was 1.2 million in 2012 compared with 93,000 in 1962. About 835,000 Indonesians were living as migrants out of their country in 2012 compared with 107,000 in 1962. The Philippines had 650,000 of its citizens living outside the country by 2012.

In terms of destination, the U.S. had 4.5 million migrants in 2012, up from 1.8 million in 1962. Germany hosted 1.8 million migrants in 2012, up from 667,000 migrants in 1962.

Russia on the other hand hosted 1 million migrants in 2012 while it had 1.4 million of its citizens living outside in 1962. A reversal of trend between 2012 and 1962 was also seen with Japan which had 358,000 migrants in 2012 while 151,000 Japanese had migrated out of the country in 1962. Malaysia also exhibits this reversing trend with 782,000 migrant workers living in the country in 2012 while 49,000 of its citizens had moved out of the country in 1962.

In the opposite reversal, Libya had 433,000 people living outside its shores in 2012 while it had housed 46,000 migrants in 1962.

In terms of huge increases in migrants into a country, Lebanon hosted 1.25 million people in 2012 compared with 20,000 in 1962 while Jordan hosted 975,000 migrants in 2012 compared with 35,000 in 1962.