Question: Since 1850, how much of the glaciation in the country of citizenship of the composer of Abschieds-Rufe has disappeared?

full_context: Document 1: Alps: The Alps provide lowland Europe with drinking water, irrigation, and hydroelectric power. Although the area is only about 11 percent of the surface area of Europe, the Alps provide up to 90 percent of water to lowland Europe, particularly to arid areas and during the summer months. Cities such as Milan depend on 80 percent of water from Alpine runoff. Water from the rivers is used in over 500 hydroelectricity power plants, generating as much as 2900 kilowatts of electricity.
Document 2: Frédéric Chopin: At the funeral of the tenor Adolphe Nourrit in Paris in 1839, Chopin made a rare appearance at the organ, playing a transcription of Franz Schubert's lied Die Gestirne. On 26 July 1840 Chopin and Sand were present at the dress rehearsal of Berlioz's Grande symphonie funèbre et triomphale, composed to commemorate the tenth anniversary of the July Revolution. Chopin was reportedly unimpressed with the composition.
Document 3: Abschieds-Rufe: Abschieds-Rufe ("Cries of Farewell"), op, 179, is a waltz composed by Johann Strauss II. It premiered in January 1856 at a ball attended by some two thousand guests in the Sofienbad-Saal in Vienna. The waltz was very well received, and was repeated four times.
Document 4: Buckingham Palace: Before Prince Albert's death, the palace was frequently the scene of musical entertainments, and the greatest contemporary musicians entertained at Buckingham Palace. The composer Felix Mendelssohn is known to have played there on three occasions. Johann Strauss II and his orchestra played there when in England. Strauss's "Alice Polka" was first performed at the palace in 1849 in honour of the queen's daughter, Princess Alice. Under Victoria, Buckingham Palace was frequently the scene of lavish costume balls, in addition to the usual royal ceremonies, investitures and presentations.
Document 5: Frédéric Chopin: Mozart's Requiem was sung at the funeral; the soloists were the soprano Jeanne-Anais Castellan, the mezzo-soprano Pauline Viardot, the tenor Alexis Dupont, and the bass Luigi Lablache; Chopin's Preludes No. 4 in E minor and No. 6 in B minor were also played. The organist at the funeral was Louis Lefébure-Wély. The funeral procession to Père Lachaise Cemetery, which included Chopin's sister Ludwika, was led by the aged Prince Adam Czartoryski. The pallbearers included Delacroix, Franchomme, and Camille Pleyel. At the graveside, the Funeral March from Chopin's Piano Sonata No. 2 was played, in Reber's instrumentation.
Document 6: Vienna Walzer Orchestra: The Vienna Walzer Orchestra (German: Wiener Walzer Orchester) is a chamber orchestra based in Vienna, Austria that specializes in traditional Viennese waltzes, polkas, marches and operetta arias from composers such as: J. Strauss II, F. Lehár, C.M. Ziehrer, among others. Their concerts also always include performances by ballet dancers and opera singers.
Document 7: Alps: The Alps are a classic example of what happens when a temperate area at lower altitude gives way to higher-elevation terrain. Elevations around the world that have cold climates similar to those of the polar regions have been called Alpine. A rise from sea level into the upper regions of the atmosphere causes the temperature to decrease (see adiabatic lapse rate). The effect of mountain chains on prevailing winds is to carry warm air belonging to the lower region into an upper zone, where it expands in volume at the cost of a proportionate loss of temperature, often accompanied by precipitation in the form of snow or rain. The height of the Alps is sufficient to divide the weather patterns in Europe into a wet north and a dry south because moisture is sucked from the air as it flows over the high peaks.
Document 8: Hotel Sacher: The Hotel Sacher is a five-star hotel located in the Innere Stadt first district of Vienna, Austria, vis-à-vis to the Vienna State Opera. It is famous for the specialty of the house, the Sachertorte, a chocolate cake with apricot filling. There is also an art gallery in the hotel with works from the 19th century. The hotel is built near the former residence of Antonio Vivaldi.
Document 9: Alps: Glaciers end in ice caves (the Rhone Glacier), by trailing into a lake or river, or by shedding snowmelt on a meadow. Sometimes a piece of glacier will detach or break resulting in flooding, property damage and loss of life. In the 17th century about 2500 people were killed by an avalanche in a village on the French-Italian border; in the 19th century 120 homes in a village near Zermatt were destroyed by an avalanche.
Document 10: Switzerland: Switzerland lies between latitudes 45° and 48° N, and longitudes 5° and 11° E. It contains three basic topographical areas: the Swiss Alps to the south, the Swiss Plateau or Central Plateau, and the Jura mountains on the west. The Alps are a high mountain range running across the central-south of the country, comprising about 60% of the country's total area. The majority of the Swiss population live in the Swiss Plateau. Among the high valleys of the Swiss Alps many glaciers are found, totalling an area of 1,063 square kilometres (410 sq mi). From these originate the headwaters of several major rivers, such as the Rhine, Inn, Ticino and Rhône, which flow in the four cardinal directions into the whole of Europe. The hydrographic network includes several of the largest bodies of freshwater in Central and Western Europe, among which are included Lake Geneva (also called le Lac Léman in French), Lake Constance (known as Bodensee in German) and Lake Maggiore. Switzerland has more than 1500 lakes, and contains 6% of Europe's stock of fresh water. Lakes and glaciers cover about 6% of the national territory. The largest lake is Lake Geneva, in western Switzerland shared with France. The Rhône is both the main source and outflow of Lake Geneva. Lake Constance is the second largest Swiss lake and, like the Lake Geneva, an intermediate step by the Rhine at the border to Austria and Germany. While the Rhône flows into the Mediterranean Sea at the French Camarque region and the Rhine flows into the North Sea at Rotterdam in the Netherlands, about 1000 km apart, both springs are only about 22 km apart from each other in the Swiss Alps.
Document 11: Paroxysmen: Paroxysmen ("Paroxysms"), opus 189, is a waltz composed by Johann Strauss II. It was dedicated to the Gentlemen Students of Medicine at Vienna University" on the occasion of a ball held in the Sofienbad-Saal in January 1857. A critic of the newspaper Fremden-Blatt commented on the waltz: "The day before yesterday the Medical Students' Ball opened the season in the Sofienbad-Saal, which made the ball especially interesting when one saw for the first time the new and sumptuously decorated locale. The dance hall is newly hung throughout with red and gold drapery, the ceiling very tastefully prepared. Little statues, surrounded by flowers and leaves, heighten the appeal of the decorations. The music was personally conducted by Strauss and his waltz 'Paroxysmen', written especially for this ball, belongs to his best compositions."
Document 12: Johann Strauss III: Despite his keen interest in composing, he was better remembered as a conductor. His only stage work, the three-act operetta "Katze und Maus", composed in 1898, premiered in Vienna on 23 December 1898, at the Theater an der Wien. Its public reaction bordered on utter dislike, and music critics called for the distraught composer to reassess himself and to appear under a pseudonym, in order not to tarnish the name of his famous relatives. He salvaged the music score and produced independent pieces of which the waltzes "Sylvanien", Op. 1 and "Leonie", Op. 2 survived obscurity.
Document 13: Alps: High levels of precipitation cause the glaciers to descend to permafrost levels in some areas whereas in other, more arid regions, glaciers remain above about the 3,500 m (11,483 ft) level. The 1,817 square kilometres (702 sq mi) of the Alps covered by glaciers in 1876 had shrunk to 1,342 km2 (518 sq mi) by 1973, resulting in decreased river run-off levels. Forty percent of the glaciation in Austria has disappeared since 1850, and 30% of that in Switzerland.
Document 14: Classical period (music): However, Vienna's fall as the most important musical center for orchestral composition during the late 1820s, precipitated by the deaths of Beethoven and Schubert, marked the Classical style's final eclipse -- and the end of its continuous organic development of one composer learning in close proximity to others. Franz Liszt and Frédéric Chopin visited Vienna when they were young, but they then moved on to other cities. Composers such as Carl Czerny, while deeply influenced by Beethoven, also searched for new ideas and new forms to contain the larger world of musical expression and performance in which they lived.
Document 15: Waltzes from Vienna: Waltzes from Vienna is a 1934 British musical film directed by Alfred Hitchcock, also known as Strauss' Great Waltz. It was part of the cycle of operetta films made in Britain during the 1930s.
ground_truth: Forty percent
sub_queries: Abschieds-Rufe >> composer Answer: Johann Strauss II
Johann Strauss II >> country of citizenship Answer: Austria
How much of the glaciation in Austria disappeared? Answer: Forty percent