Question: How much of the glaciation has disappeared in the country where the composer of Der lustige krieg was a citizen?

<P0-S0> Der lustige Krieg ("The Merry War") is a three-act operetta composed by Johann Strauss II. <P0-S1> The work was first performed on 25 November 1881 at the Theater an der Wien. <P0-S2> Its libretto was by F Zell (Camillo Walzel) and Richard Genée. <P0-S3> The operetta was well received at its premiere, and was performed 69 times during its first run. <SEP> <P1-S0> during the wisconsinan glaciation, the new york city region was situated at the edge of a large ice sheet over 1,000 feet in depth. <P1-S1> the ice sheet scraped away large amounts of soil, leaving the bedrock that serves as the geologic foundation for much of new york city today. <P1-S2> later on, the ice sheet would help split apart what are now long island and staten island. <SEP> <P2-S0> 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. <P2-S1> 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. <P2-S2> Forty percent of the glaciation in Austria has disappeared since 1850, and 30% of that in Switzerland. <SEP> <P3-S0> the rohingya people have consistently faced human rights abuses by the burmese regime that has refused to acknowledge them as burmese citizens (despite some of them having lived in burma for over three generations)—the rohingya have been denied burmese citizenship since the enactment of a 1982 citizenship law. <P3-S1> the law created three categories of citizenship: citizenship, associate citizenship, and naturalised citizenship. <P3-S2> citizenship is given to those who belong to one of the national races such as kachin, kayah (karenni), karen, chin, burman, mon, rakhine, shan, kaman, or zerbadee. <P3-S3> associate citizenship is given to those who cannot prove their ancestors settled in myanmar before 1823, but can prove they have one grandparent, or pre-1823 ancestor, who was a citizen of another country, as well as people who applied for citizenship in 1948 and qualified then by those laws. <P3-S4> naturalized citizenship is only given to those who have at least one parent with one of these types of burmese citizenship or can provide "conclusive evidence" that their parents entered and resided in burma prior to independence in 1948. the burmese regime has attempted to forcibly expel rohingya and bring in non-rohingyas to replace them—this policy has resulted in the expulsion of approximately half of the 800,000 rohingya from burma, while the rohingya people have been described as "among the world's least wanted" and "one of the world's most persecuted minorities." <P3-S5> but the origin of ‘most persecuted minority’ statement is unclear. <SEP> <P4-S0> 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. <P4-S1> Ziehrer, among others. <P4-S2> Their concerts also always include performances by ballet dancers and opera singers.