The 20th century came to be called an age of migration. The beginning of the new, 21st century has swept growing masses of people in the movement of international migrations. In 2006 two million Poles were staying outside their country as émigrés. The greatest number, around 580 thousand chose Great Britain, and 450 thousand - Germany. In 2006 in Poland there were approximately 200 thousand immigrants, mostly from Ukraine. Countries with the greatest number of emigrants in 2005 include first of all the USA - 38.4 million migrants (20.2 per cent of all inhabitants), Russia 12.1 million (6.4 per cent) and Germany - 10.1 million (5.3 per cent). Enlargement of the European Union in 2004 by accession of the new states of Central-Eastern Europe resulted among others in a complete or partial opening of the work market in the 'old' member states of the EU. This fact contributed to an increase in economic migrations causing numerous consequences e.g. for the Polish work market.