Read this: As the Grand Duchy of Finland was part of the Russian Empire from 1809 to 1918, a number of Russian speakers have remained in Finland. There are 33,400 Russian-speaking Finns, amounting to 0.6% of the population. Five thousand (0.1%) of them are late 19th century and 20th century immigrants or their descendants, and the remaining majority are recent immigrants who moved there in the 1990s and later.[citation needed] Russian is spoken by 1.4% of the population of Finland according to a 2014 estimate from the World Factbook.
Now answer this question, if there is an answer (If it cannot be answered, return "unanswerable"): When did Finland join the Russian Empire?
1809