Singapore is a tightly-controlled city state, but it is also one of the richest places in Asia, a center for international business, and welcomes immigrants.

Chinese are already the city's largest ethnic group, making up around 70% of the population.

There are 5.4 million people living in Singapore, and around 500,000 of those are permanent residents -- often highly skilled foreigners that are not citizens. The country is also home to hundreds of thousands of lower-income migrant workers.

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