Question: How much of the glaciation disappeared in the country where Otto Furrer was born?

full_context: Document 1: Alps: The region is serviced by 4,200 km (2,600 mi) of roads used by 6 million vehicles. Train travel is well established in the Alps, with, for instance 120 km (75 mi) of track for every 1,000 km2 (390 sq mi) in a country such as Switzerland. Most of Europe's highest railways are located there. Moreover, plans are underway to build a 57 km (35 mi)-long sub-alpine tunnel connecting the older Lötschberg and Gotthard tunnels built in the 19th century.
Document 2: Alps: At present the Alps are one of the more popular tourist destinations in the world with many resorts such Oberstdorf, in Bavaria, Saalbach in Austria, Davos in Switzerland, Chamonix in France, and Cortina d'Ampezzo in Italy recording more than a million annual visitors. With over 120 million visitors a year tourism is integral to the Alpine economy with much it coming from winter sports although summer visitors are an important component of the tourism industry.
Document 3: 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 4: Alps: During the post-World War I period ski-lifts were built in Swiss and Austrian towns to accommodate winter visitors, but summer tourism continued to be important; by the mid-20th century the popularity of downhill skiing increased greatly as it became more accessible and in the 1970s several new villages were built in France devoted almost exclusively to skiing, such as Les Menuires. Until this point Austria and Switzerland had been the traditional and more popular destinations for winter sports, but by the end of the 20th century and into the early 21st century, France, Italy and the Tyrol began to see increases in winter visitors. From 1980 to the present, ski-lifts have been modernized and snow-making machines installed at many resorts, leading to concerns regarding the loss of traditional Alpine culture and questions regarding sustainable development as the winter ski industry continues to develop quickly and the number of summer tourists decline.
Document 5: Franz Klammer: Franz Klammer (born 3 December 1953) is a former champion alpine ski racer from Austria. Klammer overwhelmingly dominated the downhill event for four consecutive World Cup seasons (1975-78). He was the gold medalist at the 1976 Winter Olympics in Innsbruck, winning the downhill at Patscherkofel by a margin of 0.33 seconds with a time of 1:45.73. He won 25 World Cup downhills, including four on the Hahnenkamm at Kitzbühel. He holds the record for the most victories (four) on the full course at Kitzbühel.
Document 6: 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 7: Alps: In the first half of the 20th century the Olympic Winter Games were held three times in Alpine venues: the 1924 Winter Olympics in Chamonix, France; the 1928 Winter Olympics in St. Moritz, Switzerland; and the 1936 Winter Olympics in Garmisch-Partenkirchen, Germany. During World War II the winter games were canceled but after that time the Winter Games have been held in St. Moritz (1948), Cortina d'Ampezzo (1956), Innsbruck, Austria (1964 and 1976), Grenoble, France, (1968), Albertville, France, (1992), and Torino (2006). In 1930 the Lauberhorn Rennen (Lauberhorn Race), was run for the first time on the Lauberhorn above Wengen; the equally demanding Hahnenkamm was first run in the same year in Kitzbühl, Austria. Both races continue to be held each January on successive weekends. The Lauberhorn is the more strenuous downhill race at 4.5 km (2.8 mi) and poses danger to racers who reach 130 km/h (81 mph) within seconds of leaving the start gate.
Document 8: Alps: The lower regions and larger towns of the Alps are well-served by motorways and main roads, but higher mountain passes and byroads, which are amongst the highest in Europe, can be treacherous even in summer due to steep slopes. Many passes are closed in winter. A multitude of airports around the Alps (and some within), as well as long-distance rail links from all neighbouring countries, afford large numbers of travellers easy access from abroad.
Document 9: 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 10: FIS Alpine World Ski Championships 1932: The FIS Alpine World Ski Championships 1932 were held 4–6 February in Cortina d'Ampezzo, Italy. These were the second world championships and the combined event was added to the program. The first edition was held the prior year in Mürren, Switzerland.
Document 11: Otto Furrer: Furrer was born in Zermatt. He became a world champion in the combined event, received a silver medal in the slalom and a bronze medal in the downhill in Cortina d'Ampezzo in 1932. He was killed in an accident on the Matterhorn.
Document 12: 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 13: Wolfgang Junginger: Wolfgang Junginger (27 October 1951 – 17 February 1982) was a German alpine skier who competed in the 1976 Winter Olympics. There he finished on 6th place in Special Slalom and on 4th place in Alpine Combined. Two years before, in World Championships at St. Moritz (Switzerland), he won the bronze medal in Alpine Combined. Mr. Junginger died in an airplane crash when he piloted a small airplane from Munich to Hannover in Germany. Including the pilot himself there were four persons in the plane and one of them was Mr. Ulrich Hoeness, well known manager of Bayern Munich. Mr. Hoeness was the only one who had survived the accident.
Document 14: Alps: Some high mountain villages, such as Avoriaz (in France), Wengen, and Zermatt (in Switzerland) are accessible only by cable car or cog-rail trains, and are car free. Other villages in the Alps are considering becoming car free zones or limiting the number of cars for reasons of sustainability of the fragile Alpine terrain.
Document 15: 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.
ground_truth: 30%
sub_queries: Otto Furrer >> place of birth Answer: Zermatt
Where are the villages of Wengen and Zermatt located? Answer: Switzerland
How much of the glaciation disappeared in Switzerland ? Answer: 30%