Question: How long was the population decline caused by the Great Irish Famine in the country where the performer of "Ordinary Man" is from?

full_context: Document 1: Mandolin: Noteworthy Irish mandolinists include Andy Irvine (who, like Johnny Moynihan, almost always tunes the top E down to D, to achieve an open tuning of GDAD), Paul Brady, Mick Moloney, Paul Kelly and Claudine Langille. John Sheahan and the late Barney McKenna, respectively fiddle player and tenor banjo player with The Dubliners, are also accomplished Irish mandolin players. The instruments used are either flat-backed, oval hole examples as described above (made by UK luthier Roger Bucknall of Fylde Guitars), or carved-top, oval hole instruments with arched back (made by Stefan Sobell in Northumberland). The Irish guitarist Rory Gallagher often played the mandolin on stage, and he most famously used it in the song "Going To My Hometown."
Document 2: Ordinary Man (Christy Moore album): Ordinary Man is the tenth studio album by Irish folk artist, Christy Moore. It features songs like "Ordinary Man", "St. Brendan's Voyage" and "Another Song is Born".
Document 3: British Isles: Hiberni (Ireland), Pictish (northern Britain) and Britons (southern Britain) tribes, all speaking Insular Celtic, inhabited the islands at the beginning of the 1st millennium AD. Much of Brittonic-controlled Britain was conquered by the Roman Empire from AD 43. The first Anglo-Saxons arrived as Roman power waned in the 5th century and eventually dominated the bulk of what is now England. Viking invasions began in the 9th century, followed by more permanent settlements and political change—particularly in England. The subsequent Norman conquest of England in 1066 and the later Angevin partial conquest of Ireland from 1169 led to the imposition of a new Norman ruling elite across much of Britain and parts of Ireland. By the Late Middle Ages, Great Britain was separated into the Kingdoms of England and Scotland, while control in Ireland fluxed between Gaelic kingdoms, Hiberno-Norman lords and the English-dominated Lordship of Ireland, soon restricted only to The Pale. The 1603 Union of the Crowns, Acts of Union 1707 and Acts of Union 1800 attempted to consolidate Britain and Ireland into a single political unit, the United Kingdom of Great Britain and Ireland, with the Isle of Man and the Channel Islands remaining as Crown Dependencies. The expansion of the British Empire and migrations following the Irish Famine and Highland Clearances resulted in the distribution of the islands' population and culture throughout the world and a rapid de-population of Ireland in the second half of the 19th century. Most of Ireland seceded from the United Kingdom after the Irish War of Independence and the subsequent Anglo-Irish Treaty (1919–1922), with six counties remaining in the UK as Northern Ireland.
Document 4: Burning Times (album): Burning Times is an album by Irish folk singer Christy Moore. The album is dedicated to Rachel Corrie, an American activist killed by an Israeli bulldozer in Gaza in 2003.
Document 5: British Isles: The population of England rose rapidly during the 19th and 20th centuries whereas the populations of Scotland and Wales have shown little increase during the 20th century, with the population of Scotland remaining unchanged since 1951. Ireland for most of its history comprised a population proportionate to its land area (about one third of the total population). However, since the Great Irish Famine, the population of Ireland has fallen to less than one tenth of the population of the British Isles. The famine, which caused a century-long population decline, drastically reduced the Irish population and permanently altered the demographic make-up of the British Isles. On a global scale, this disaster led to the creation of an Irish diaspora that numbers fifteen times the current population of the island.
Document 6: British Isles: The Kingdoms of England and Scotland were unified in 1707 creating the Kingdom of Great Britain. Following an attempted republican revolution in Ireland in 1798, the Kingdoms of Ireland and Great Britain were unified in 1801, creating the United Kingdom. The Isle of Man and the Channel Islands remaining outside of the United Kingdom but with their ultimate good governance being the responsibility of the British Crown (effectively the British government). Although, the colonies of North American that would become the United States of America were lost by the start of the 19th century, the British Empire expanded rapidly elsewhere. A century later it would cover one third of the globe. Poverty in the United Kingdom remained desperate however and industrialisation in England led to terrible condition for the working class. Mass migrations following the Irish Famine and Highland Clearances resulted in the distribution of the islands' population and culture throughout the world and a rapid de-population of Ireland in the second-half of the 19th century. Most of Ireland seceded from the United Kingdom after the Irish War of Independence and the subsequent Anglo-Irish Treaty (1919–1922), with the six counties that formed Northern Ireland remaining as an autonomous region of the UK.
Document 7: Paddy on the Road: Paddy on the Road is the debut album by Irish folk musician Christy Moore, released in 1969. The album was produced and co-written by Dominic Behan. Steve Benbow organised the backing musicians and was responsible for the arrangements and conducting.
Document 8: Listen (Christy Moore album): Listen is an album by Irish folk singer Christy Moore, released in Ireland on 17 April 2009 by Columbia Records. Recorded with long-time accompanist Declan Sinnott, it is his first studio album since 2005's "Burning Times". The album debuted at number one on the Irish Albums Chart.
Document 9: Live at the Point (1994 Christy Moore album): Live at the Point is a live album by Irish folk singer Christy Moore, released in 1994. The album was recorded at the Point Theatre in Dublin over a course of a number of concerts in 1994.
Document 10: Stuff (Eleanor McEvoy album): STUFF is Eleanor McEvoy's eleventh studio album. The tracks on the album were compiled to meet the requests from fans for songs they couldn't find elsewhere. McEvoy chose the songs from her collection of single mixes, audiophile tracks, and songs written and performed on other artists records. McEvoy then went into the studio to record tracks that weren't found in her collection. After all songs were recorded the entire album was re-mastered. On 14 March 2014 Stuff was named Album of the Week on RTÉ Radio 1
Document 11: The Iron Behind the Velvet: The Iron Behind the Velvet is an album recorded by Christy Moore in 1978, after the first breakup of Planxty. It was produced jointly by Brian Masterson and Moore, and recorded and mixed at Lombard and Keystone Studios, Dublin.
Document 12: British Isles: The demographics of the British Isles today are characterised by a generally high density of population in England, which accounts for almost 80% of the total population of the islands. In elsewhere on Great Britain and on Ireland, high density of population is limited to areas around, or close to, a few large cities. The largest urban area by far is the Greater London Urban Area with 9 million inhabitants. Other major populations centres include Greater Manchester Urban Area (2.4 million), West Midlands conurbation (2.4 million), West Yorkshire Urban Area (1.6 million) in England, Greater Glasgow (1.2 million) in Scotland and Greater Dublin Area (1.1 million) in Ireland.[citation needed]
Document 13: Ride On (Christy Moore album): Ride On is an album by Irish folk singer Christy Moore, released in 1984. Its title track remains one of his most popular songs. A number of songs relate the actions of those involved in political struggles, or those affected by those struggles; such as "Viva la Quinte Brigada" which is concerned with the Irish contingent amongst the International Brigade in the Spanish Civil War; or "El Salvador" dealing with the civil war in that country in the 1980s. Other songs deal with Irish history – "The City of Chicago", about emigration to America during the Irish famines of the late 1840s; "Back Home in Derry" written by Bobby Sands about the transportation to Australia of convicts; and "Lisdoonvarna" celebrating a music festival that took place annually in that town until the early 1980s.
Document 14: The Keeper of the Stars: Initially, Byrd's label (MCA Records) had not planned for "The Keeper of the Stars" to be a single, until his publicist realized that the song had been receiving positive feedback for it in concert. The fourth single from Byrd's "No Ordinary Man" album, "The Keeper of the Stars" spent twenty weeks on the "Billboard" Hot Country Singles & Tracks (now Hot Country Songs) charts, reaching a peak position of number two.
Document 15: British Empire: Political boundaries drawn by the British did not always reflect homogeneous ethnicities or religions, contributing to conflicts in formerly colonised areas. The British Empire was also responsible for large migrations of peoples. Millions left the British Isles, with the founding settler populations of the United States, Canada, Australia and New Zealand coming mainly from Britain and Ireland. Tensions remain between the white settler populations of these countries and their indigenous minorities, and between white settler minorities and indigenous majorities in South Africa and Zimbabwe. Settlers in Ireland from Great Britain have left their mark in the form of divided nationalist and unionist communities in Northern Ireland. Millions of people moved to and from British colonies, with large numbers of Indians emigrating to other parts of the empire, such as Malaysia and Fiji, and Chinese people to Malaysia, Singapore and the Caribbean. The demographics of Britain itself was changed after the Second World War owing to immigration to Britain from its former colonies.
ground_truth: century-long population decline
sub_queries: Ordinary Man >> performer Answer: Christy Moore
Christy Moore >> country of citizenship Answer: Ireland
How long did the Great Irish Famine cause a population decline in Ireland ? Answer: century-long population decline