Finland has a population of 5.26 million people and its capital and largest city is Helsinki. Finnish is the official language, though ethnic groups also speak their own languages. 91% of the population practices Christianity. Finland has one of the best education systems in the world, with compulsory schooling starting at age 7 and no grading in the first six years. The Northern Lights are a remarkable feature visible in Finland's night sky, which some immigrate to see.