Question: When did the country where the Cobra rollercoaster is located join the Russian Empire?

full_context: Document 1: Diavlo: Diavlo is a steel roller coaster at Himeji Central Park in Japan which is a clone of Batman the Ride. It is one of the first Bolliger & Mabillard roller coasters to be located outside of the United States, and the second by launch date; opening four months later than Nemesis at Alton Towers, England.
Document 2: Russian language: 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.
Document 3: Cedar Point: Cedar Point is a 364 - acre (147 ha) amusement park located on a Lake Erie peninsula in Sandusky, Ohio. Opened in 1870, it is the second - oldest operating amusement park in the United States behind Lake Compounce. Cedar Point is owned and operated by Cedar Fair and is considered the flagship of the amusement park chain. Known as ``America's Roller Coast '', the park features a world - record 72 rides, including 16 roller coasters -- the second-most in the world behind Six Flags Magic Mountain. Its newest roller coaster, Steel Vengeance, is set to open in May 2018.
Document 4: Tranan: Tranan () is a steel suspended roller coaster at the Skara Sommarland amusement park in Sweden. Opening in May 2009, the ride is S&S Worldwide's first and only Free Fly roller coaster.
Document 5: History of the roller coaster: In 1959, the Disneyland theme park introduced a new design breakthrough in roller coasters with the Matterhorn Bobsleds. This was the first roller coaster to use a tubular steel track. Unlike conventional wooden rails, which are generally formed using steel strips mounted on laminated wood, tubular steel can be bent in any direction, which allows designers to incorporate loops, corkscrews, and many other maneuvers into their designs. Most modern roller coasters are made of steel, although wooden roller coasters are still being built along with hybrids of steel and wood.
Document 6: Russian language: In Kazakhstan Russian is not a state language, but according to article 7 of the Constitution of Kazakhstan its usage enjoys equal status to that of the Kazakh language in state and local administration. According to estimates from Demoskop Weekly, in 2004 there were 4,200,000 native speakers of Russian in the country, and 10 million active speakers. 63% of the population was fluent in Russian in 2006, and 46% used it as the main language with family, friends or at work. According to a 2001 estimate from the World Factbook, 95% of the population can speak Russian. Large Russian-speaking communities still exist in northern Kazakhstan, and ethnic Russians comprise 25.6% of Kazakhstan's population. The 2009 census reported that 10,309,500 people, or 84.8% of the population aged 15 and above, could read and write well in Russian, as well as understand the spoken language.
Document 7: Russian language: The language was first introduced in North America when Russian explorers voyaged into Alaska and claimed it for Russia during the 1700s. Although most colonists left after the United States bought the land in 1867, a handful stayed and preserved the Russian language in this region to this day, although only a few elderly speakers of this unique dialect are left. Sizable Russian-speaking communities also exist in North America, especially in large urban centers of the U.S. and Canada, such as New York City, Philadelphia, Boston, Los Angeles, Nashville, San Francisco, Seattle, Spokane, Toronto, Baltimore, Miami, Chicago, Denver and Cleveland. In a number of locations they issue their own newspapers, and live in ethnic enclaves (especially the generation of immigrants who started arriving in the early 1960s). Only about 25% of them are ethnic Russians, however. Before the dissolution of the Soviet Union, the overwhelming majority of Russophones in Brighton Beach, Brooklyn in New York City were Russian-speaking Jews. Afterward, the influx from the countries of the former Soviet Union changed the statistics somewhat, with ethnic Russians and Ukrainians immigrating along with some more Russian Jews and Central Asians. According to the United States Census, in 2007 Russian was the primary language spoken in the homes of over 850,000 individuals living in the United States.
Document 8: Russian language: Significant Russian-speaking groups also exist in Western Europe. These have been fed by several waves of immigrants since the beginning of the 20th century, each with its own flavor of language. The United Kingdom, Spain, Portugal, France, Italy, Belgium, Greece, Brazil, Norway, and Austria have significant Russian-speaking communities. According to the 2011 Census of Ireland, there were 21,639 people in the nation who use Russian as a home language. However, of this only 13% were Russian nationals. 20% held Irish citizenship, while 27% and 14% were holding the passports of Latvia and Lithuania respectively.
Document 9: Twisted Cyclone: Twisted Cyclone, formerly known as Georgia Cyclone, is a steel roller coaster located at Six Flags Over Georgia in Austell, Georgia. Manufactured by Rocky Mountain Construction (RMC), it was opened to the public on May 25, 2018. It features RMC's patented I - Box Track technology utilizing a significant portion of Georgia Cyclone's former support structure. Originally constructed by the Dinn Corporation, the roller coaster originally opened as Georgia Cyclone on March 3, 1990. It closed for the planned transformation in 2017.
Document 10: Cobra (PowerPark): Cobra is a roller coaster located at PowerPark in Alahärmä, Finland. "Cobra" was the first Vekoma boomerang to use the new MK1211 open sided train.
Document 11: Raptor (Cedar Point): Raptor is a steel inverted roller coaster designed by Bolliger & Mabillard at Cedar Point in Sandusky, Ohio, United States. When built in 1994, it broke many records and held many firsts when it opened. Instead of having a short layout designed to fit into a compact area like , Raptor was designed with a larger, 3,790-foot (1,160 m) layout, making it the tallest, fastest and longest inverted roller coaster in the world when it opened. It features six inversions, including a cobra roll, a first for inverted roller coasters. At its opening, it was the largest investment in Cedar Point history. The ride is themed as a bird of prey.
Document 12: Russian language: According to figures published in 2006 in the journal "Demoskop Weekly" research deputy director of Research Center for Sociological Research of the Ministry of Education and Science (Russia) Arefyev A. L., the Russian language is gradually losing its position in the world in general, and in Russia in particular. In 2012, A. L. Arefyev published a new study "Russian language at the turn of the 20th-21st centuries", in which he confirmed his conclusion about the trend of further weakening of the Russian language in all regions of the world (findings published in 2013 in the journal "Demoskop Weekly"). In the countries of the former Soviet Union the Russian language is gradually being replaced by local languages. Currently the number speakers of Russian language in the world depends on the number of Russians in the world (as the main sources distribution Russian language) and total population Russia (where Russian is an official language).
Document 13: Volcano: The Blast Coaster: Volcano, The Blast Coaster, or simply Volcano, is a launched inverted roller coaster at Kings Dominion in Doswell, Virginia. Designed by both Paramount Parks and Werner Stengel and built by Intamin, Volcano was the world's first inverted roller coaster to feature an LIM (linear induction motor) and is the only one of its kind that completes a full circuit. Since its opening on August 3, 1998, Volcano has been one of the more popular rides in the park. Most of Volcano's circuit is located inside a man - made volcano, making it an enclosed roller coaster.
Document 14: Russian language: Ethnic Russians constitute 25.5% of the country's current population and 58.6% of the native Estonian population is also able to speak Russian. In all, 67.8% of Estonia's population can speak Russian. Command of Russian language, however, is rapidly decreasing among younger Estonians (primarily being replaced by the command of English). For example, if 53% of ethnic Estonians between 15 and 19 claim to speak some Russian, then among the 10- to 14-year-old group, command of Russian has fallen to 19% (which is about one-third the percentage of those who claim to have command of English in the same age group).
Document 15: Russian language: In Georgia Russian has no official status, but it's recognised as a minority language under the Framework Convention for the Protection of National Minorities. According to estimates from Demoskop Weekly, in 2004 there were 130,000 native speakers of Russian in the country, and 1.7 million active speakers. 27% of the population was fluent in Russian in 2006, and 1% used it as the main language with family, friends or at work. Russian is the language of 9% of the population according to the World Factook. Ethnologue cites Russian as the country's de facto working language.
ground_truth: 1809
sub_queries: Cobra >> country Answer: Finland
When did Finland join the Russian Empire? Answer: 1809