According to the government of Great Britain, 2.5 million Britons emigrated to other countries between the years 2000 and 2009. Those immigrants alone made up 4.5% of the entire UK population that year. It's a statistic that's certainly struck a chord with European countries, who want to improve their economic potential in ways that are more "open." Today the British government released its latest research into the migration of EU citizens to other countries in the EU and Switzerland. The numbers are staggering. In the years 2000-2009, the UK's population shrank by around 11 million people. The UK's population as a whole grew by just 5.4% between 1990 and 2000. The ratio of UK-born citizens to foreign-born citizens, also known as "naturalization rate," fell from an all-time high of 13% in 1990 to an all-time low of 8.3% in 2011. The UK's naturalization rate among foreign-born people also declined, which highlights the divide between countries with a larger number of immigrants and the countries with a greater presence of foreigners overall. EU citizens constituted 14% of the UK population in 2005, but they accounted for 24% of naturalization across the EU. That's a dramatic difference from the UK itself. Of the British population, about 27% were foreign born, and the percentage of foreign-born citizens in the UK's total population increased by nearly 40% between 1990 and 2000. Unlike the United States, which is heavily reliant on immigration and immigration was a leading factor in driving the country's economic growth throughout the second half of the 20th century, it looks like there are some international policy and policy-making trends that lead the UK to the conclusion that it would be a wise investment to remain in the EU. One notable difference is that it's been suggested that the UK could benefit from controlling or reducing its immigration from EU countries by imposing border controls between the UK and EU. This is in stark contrast to the US, which faces a high potential for additional immigration from non-EU countries, given the rise of countries like Mexico and Central and South America.That said, a movement to be more "open" does not appear to be in the cards. The UK's Home Office Office made it clear that it "remains firmly committed to the principle of free movement between the UK and EU, as well as the Commonwealth and other countries in the EU."