Question: When did East Germany unite with the country where Andrea Martin has citizenship?

full_context: Document 1: Germany: After Germany surrendered, the Allies partitioned Berlin and Germany's remaining territory into four military occupation zones. The western sectors, controlled by France, the United Kingdom, and the United States, were merged on 23 May 1949 to form the Federal Republic of Germany (Bundesrepublik Deutschland); on 7 October 1949, the Soviet Zone became the German Democratic Republic (Deutsche Demokratische Republik). They were informally known as West Germany and East Germany. East Germany selected East Berlin as its capital, while West Germany chose Bonn as a provisional capital, to emphasize its stance that the two - state solution was an artificial and temporary status quo.
Document 2: German reunification: The German reunification (German: Deutsche Wiedervereinigung) was the process in 1990 in which the German Democratic Republic (GDR / DDR / East Germany) joined the Federal Republic of Germany (FRG / West Germany) to form the reunited nation of Germany, and when Berlin reunited into a single city, as provided by its then Grundgesetz constitution Article 23. The end of the unification process is officially referred to as German unity (German: Deutsche Einheit), celebrated on 3 October (German Unity Day) (German: Tag der deutschen Einheit). Following German reunification, Berlin was once again designated as the capital of united Germany.
Document 3: Territorial evolution of Germany: The territorial changes of Germany include all changes in the borders and territory of Germany from its formation in 1871 to the present. Modern Germany was formed in 1871 when Otto von Bismarck unified most of the German states, with the notable exception of Austria, into the German Empire. After the First World War, Germany lost about 10% of its territory to its neighbours and the Weimar Republic was formed. This republic included territories to the east of today's German borders.
Document 4: Claudia Österheld: Claudia Österheld (born 8 December 1968 in Kassel) is a West Germany sprint canoer who competed in the late 1980s. At the 1988 Summer Olympics in Seoul, she finished fifth in the K-4 500 m event while being eliminated in the semifinals of the K-2 500 m event.
Document 5: Christiane Krause: She competed for West Germany in the 1972 Summer Olympics held in Munich, Germany in the 4 x 100 metres where she won the gold medal with her team mates Ingrid Becker, Annegret Richter and Heide Rosendahl.
Document 6: Petra Boesler: She was born in Berlin. She is the sister of Martina Boesler, who is also an Olympic rower. Their aunt, Renate Boesler, won several medals at European Rowing Championships. Her aunt got her interested in rowing by taking her to regattas. Her aunt is married to the Olympic rower Wolfgang Gunkel.
Document 7: Martin Ebbertz: He grew up in Pruem (Eifel), and studied Germanistik, Philosophy, and History in Freiburg, Münster and Frankfurt. He lived and worked as a free-lance writer first in Frankfurt/Main, then five years in Thessaloniki, Greece. Since Spring 2000 Martin Ebbertz has lived with his wife and two children in Boppard on the Rhine River. In addition to being a writer, he is also a flea market dealer and a second-hand bookseller.
Document 8: Marcia Gudereit: Born in Moose Jaw, Saskatchewan, she was part of Team Schmirler, the women's curling team that won a gold medal at the 1998 Winter Olympics. This team is the only 3-time winner of the World Curling Championship (1993, 1994, 1997). After Sandra died, she remained in the team, now skipped by Jan Betker for whom she currently plays. She curls out of the Caledonia Curling Club in Regina, Saskatchewan and works as a systems analyst for The Co-operators.
Document 9: Dresden: Since German reunification in 1990 Dresden is again a cultural, educational and political centre of Germany and Europe. The Dresden University of Technology is one of the 10 largest universities in Germany and part of the German Universities Excellence Initiative. The economy of Dresden and its agglomeration is one of the most dynamic in Germany and ranks first in Saxony.  It is dominated by high-tech branches, often called “Silicon Saxony”. The city is also one of the most visited in Germany with 4.3 million overnight stays per year. The royal buildings are among the most impressive buildings in Europe. Main sights are also the nearby National Park of Saxon Switzerland, the Ore Mountains and the countryside around Elbe Valley and Moritzburg Castle. The most prominent building in the city of Dresden is the Frauenkirche. Built in the 18th century, the church was destroyed during World War II. The remaining ruins were left for 50 years as a war memorial, before being rebuilt between 1994 and 2005.
Document 10: States of Germany: After the Nazi Party seized power in January 1933, the Länder increasingly lost importance. They became administrative regions of a centralised country. Three changes are of particular note: on January 1, 1934, Mecklenburg-Schwerin was united with the neighbouring Mecklenburg-Strelitz; and, by the Greater Hamburg Act (Groß-Hamburg-Gesetz), from April 1, 1937, the area of the city-state was extended, while Lübeck lost its independence and became part of the Prussian province of Schleswig-Holstein.
Document 11: Berlin Wall: In 1989 a series of revolutions in nearby Eastern Bloc countries -- Poland and Hungary in particular -- caused a chain reaction in East Germany that ultimately resulted in the demise of the Wall. After several weeks of civil unrest, the East German government announced on 9 November 1989 that all GDR citizens could visit West Germany and West Berlin. Crowds of East Germans crossed and climbed onto the Wall, joined by West Germans on the other side in a celebratory atmosphere. Over the next few weeks, euphoric people and souvenir hunters chipped away parts of the Wall; the governments later used industrial equipment to remove most of what was left. The ``fall of the Berlin Wall ''paved the way for German reunification, which formally took place on 3 October 1990.
Document 12: Andrea Martin (canoeist): Andrea Martin (born 23 April 1967 in Erbach im Odenwald, Germany) is a West Germany sprint canoer who competed in the late 1980s. At the 1988 Summer Olympics in Seoul, she finished fifth in the K-4 500 m event while being eliminated in the semifinals of the K-2 500 m event.
Document 13: Martin Strege: Martin Strege (born 21 February 1966 in Kassel) is a retired German runner who specialized in the 3000 metres steeplechase.
Document 14: History of Germany (1945–1990): The intended governing body of Germany was called the Allied Control Council. The commanders - in - chief exercised supreme authority in their respective zones and acted in concert on questions affecting the whole country. Berlin, which lay in the Soviet (eastern) sector, was also divided into four sectors with the Western sectors later becoming West Berlin and the Soviet sector becoming East Berlin, capital of East Germany.
Document 15: Unification of Germany: The unification of Germany into a politically and administratively integrated nation state officially occurred on 18 January 1871, in the Hall of Mirrors at the Palace of Versailles in France. Princes of the German states, excluding Austria, gathered there to proclaim Wilhelm I of Prussia as German Emperor after the French capitulation in the Franco - Prussian War. Unofficially, the de facto transition of most of the German - speaking populations into a federated organization of states had been developing for some time through alliances formal and informal between princely rulers -- but in fits and starts; self - interests of the various parties hampered the process over nearly a century of autocratic experimentation, beginning in the era of the Napoleonic Wars, which saw the dissolution of the Holy Roman Empire of the German Nation (1806), and the subsequent rise of German nationalism.
ground_truth: 1990
sub_queries: Andrea Martin >> country of citizenship Answer: West Germany
when did east germany and West Germany unite Answer: 1990