Question: The Plymouth City Airport was officially opened by a man that was King of the UK until what year?

Context articles: New Plymouth
Air Southwest
RAF Roborough
Roborough
Brymon Airways
Plymouth City Council election, 2016
Hele's School
Edward VIII
Plymouth City Airport
Plymouth City Council election, 2014

New Plymouth (Māori: "Ngāmotu" ) is the major city of the Taranaki Region on the west coast of the North Island of New Zealand.
 It is named after the English city of Plymouth from where the first English settlers migrated.
 The New Plymouth District includes New Plymouth City and several smaller towns.
 The New Plymouth District is the 10th largest district (out of 67) in New Zealand, and has 1.7 percent of New Zealand's population.
 The district has a population of 74,184 – about two-thirds of the total population of the Taranaki Region.
 This includes New Plymouth City (), Waitara (6,483), Inglewood (3,380), Oakura (1,359), Okato (561) and Urenui (429).
Air Southwest was a British airline founded by Sutton Harbour Holdings in 2003.
 Ownership was transferred to Eastern Airways in September 2010 but operations ceased 12 months later.
 It operated regional scheduled passenger services in the South West of England.
 Its main base was Plymouth City Airport, with hubs at Newquay Cornwall Airport and Bristol Airport.
 The airline employed 145 people and was headed by managing director Peter Davies and Deputy chief executive Mike Coombes.
RAF Roborough is a former Royal Air Force station in Roborough located 3.8 mi north of Plymouth, Devon which used Plymouth City Airport as their base.
Roborough is a village in the South Hams of Devon, England.
 Former home of Plymouth City Airport (and formerly to RAF Roborough), Roborough lies just outside the northern boundary of the city of Plymouth on the main road to Tavistock, and is a popular dormitory village.
Brymon Airways is a former British airline with its head office in the Brymon House on the property of Plymouth City Airport in Plymouth, Devon.
 It was co-founded in 1972 by journalist Bill Bryce and racing driver Chris Amon.
The 2016 Plymouth City Council election took place on 5 May 2016 to elect members of Plymouth City Council in England.
 The Conservatives gained one seat from Labour, resulting in both parties having 27 members.
 A coalition of Conservative and UKIP members took overall control of the Council, having 30 members in total and a working majority.
 The election took place on the same day as other local elections.
 It was also contested by the Plymouth Independents, a new political party formed by former UKIP members.
Hele's School, formerly Plympton Grammar School, is a state secondary school and Sixth Form in the Plympton district of Plymouth, England, 6 mi east of Plymouth city centre.
 Until 31 March 2011, Hele’s was a community school funded by the Local Education Authority (LEA), which is Plymouth City Council.
 From 1 April 2011, Hele's became an Academy, which among other things gives the school financial and educational independence.
 The school has a voluntary Combined Cadet Force with Navy, Army and RAF sections.
 Cadets in the CCF take part in the annual Ten Tors Challenge on Dartmoor.
Edward VIII (Edward Albert Christian George Andrew Patrick David; 23 June 1894 – 28 May 1972) was King of the United Kingdom and the Dominions of the British Empire, and Emperor of India, from 20 January 1936 until his abdication on 11 December the same year.
Plymouth City Airport (IATA: PLH, ICAO: EGHD) is a 'mothballed' airport located within the City of Plymouth 3.5 NM north northeast of the city centre in Devon, England at Roborough.
 The airport opened on this site in 1925 and was officially opened by the future Edward VIII, as Prince of Wales, in 1931.
 The airport is located close to the city centre and has a modern terminal.
The 2014 Plymouth City Council election took place on 22 May 2014 to elect members of Plymouth City Council in England.
 This was on the same day as other local elections.