Question: what percentage of Greenland speaks the same language that Count Flemming Valdemar of Rosenborg did?
Context: Prince Viggo, Count of Rosenborg ("Viggo Christian Adolf Georg", 25 December 1893 – 4 January 1970) was a Danish prince.  He was born in Copenhagen the youngest son of Prince Valdemar of Denmark and Princess Marie of Orléans. The reticulocyte production index (RPI), also called a corrected reticulocyte count (CRC), is a calculated value used in the diagnosis of anemia.  This calculation is necessary because the raw reticulocyte count is misleading in anemic patients.  The problem arises because the reticulocyte count is not really a "count" but rather a "percentage": it reports the number of reticulocytes as a percentage of the number of red blood cells.  In anemia, the patient's red blood cells are depleted, creating an erroneously elevated reticulocyte count. Greenlandic is an Eskimo–Aleut language spoken by about 57,000 Greenlandic Inuit in Greenland.  It is closely related to the Inuit languages in Canada such as Inuktitut.  The main variety, Kalaallisut or West Greenlandic, has been the official language of the Greenlandic autonomous territory since June 2009; this is a move by the Naalakkersuisut (government of Greenland) to strengthen the language in its competition with the colonial language, Danish.  The second variety is Tunumiit oraasiat or East Greenlandic.  The Thule Inuit of Greenland, Inuktun or Polar Eskimo, is a recent arrival and a dialect of Inuktitut. Danish ("dansk" ] ; "dansk sprog", ] ) is a North Germanic language spoken by around six million people, principally in Denmark and in the region of Southern Schleswig in northern Germany, where it has minority language status.  There are also minor Danish-speaking communities in Norway, Sweden, Spain, the United States, Canada, Brazil and Argentina.  Due to immigration and language shift in urban areas, around 15–20% of the population of Greenland speak Danish as their home language. Count Flemming Valdemar of Rosenborg (Danish: "Prins Flemming Valdemar Carl Axel til Danmark" , and later, Danish: "Greve Flemming Valdemar af Rosenborg" ; 9 March 1922, Stockholm – 19 June 2002, Antibes) was a former Danish prince. Count Ingolf of Rosenborg {'1': ", '2': ", '3': 'RE', '4': "} (born 17 February 1940) is a former Danish prince.  Born Prince Ingolf of Denmark (Danish: "Prins Ingolf Christian Frederik Knud Harald Gorm Gustav Viggo Valdemar Aage til Danmark" ), he appeared likely to some day become king until the constitution was changed in 1953 to allow females to inherit the crown, placing his branch of the dynasty behind that of his cousin Princess Margrethe and her two younger sisters.  He later gave up his princely rank and his rights to the throne in order to marry a commoner.  However, through his mother, he is a legitimate descendant of King George II of Great Britain, and retains a place in line to the British throne. Countess Anne Dorte of Rosenborg (née Anne Dorte Maltoft-Nielsen; 3 October 1947 – 2 January 2014) was a Danish countess and widow of the late Count Christian of Rosenborg (1942–2013), the grandson of King Christian X of Denmark.  Prince Christian had to give up his princely rank in order to marry her because she was a commoner.  The couple married on 7 February 1971, earning her the title "Her Excellency Countess Anne Dorte of Rosenborg". Prince Aage, Count of Rosenborg (Aage Christian Alexander Robert; June 10, 1887 – February 19, 1940), was a Danish prince and officer of the French Foreign Legion.  He was born in Copenhagen the eldest child and son of Prince Valdemar of Denmark and Princess Marie d'Orléans. Prince Erik, Count of Rosenborg (Erik Frederik Christian Alexander; 8 November 1890 – 10 September 1950) was a Danish prince.  He was born in Copenhagen, a son of Prince Valdemar of Denmark and Princess Marie of Orléans. Princess Viggo, Countess of Rosenborg (née Eleanor Margaret Green) was born on November 5, 1895 in New York City.  She was the daughter of Dr. James Oliver Green and Amelia Hewitt Green.  Her mother was daughter of Abram S. Hewitt and the granddaughter of Peter Cooper.  She married Prince Viggo of Denmark, Viggo Christian Adolph George, son of Prince Valdemar of Denmark and Marie Amélie Françoise Hélène d'Orléans, Princesse d'Orléans, on June 10, 1924 at New York City, New York, U.S.A.  She died on July 3, 1966 at age 70 at Copenhagen, Denmark.
Answer: 15–20% of the population