Question: When did the roof gardens above the neighborhood where Hansom Cab was located open to the public?

full_context: Document 1: Pembroke Square, London: Pembroke Square is located in the Kensington area of southwest central London, England (postcode W8). The whole square is Grade II listed for its architectural merit. It was developed by the Hawks family.
Document 2: Department store: The design and function of department stores in Germany followed the lead of London, Paris and New York. Germany used to have a number of department stores; nowadays only a few of them remain. Next to some smaller, independent department stores these are Karstadt (in 2010 taken over by Nicolas Berggruen, also operating the KaDeWe in Berlin, the Alsterhaus in Hamburg and the Oberpollinger in Munich), GALERIA Kaufhof (part of the Metro AG). Others like Hertie, Wertheim and Horten AG were taken over by others and either fully integrated or later closed.
Document 3: Plymouth: In 2004 the old Drake Circus shopping centre and Charles Cross car park were demolished and replaced by the latest Drake Circus Shopping Centre, which opened in October 2006. It received negative feedback before opening when David Mackay said it was already "ten years out of date". In contrast, the Theatre Royal's production and education centre, TR2, which was built on wasteland at Cattedown, was a runner-up for the RIBA Stirling Prize for Architecture in 2003.
Document 4: The Hansom Cab: The Hansom Cab is a Grade II listed public house at 84–86 Earls Court Road, Kensington, London W8 6EG. It is on the corner with Pembroke Square.
Document 5: 80 Coleman Street: 80 Coleman Street is an Edwardian building in the Moorgate area of the City of London, not far from the Guildhall. It was used for the offices of the Institute of Marine Engineering, Science and Technology, until the Institute moved to the Aldgate area.
Document 6: Pub: The Red Lion in Parliament Square is close to the Palace of Westminster and is consequently used by political journalists and members of parliament. The pub is equipped with a Division bell that summons MPs back to the chamber when they are required to take part in a vote. The Punch Bowl, Mayfair was at one time jointly owned by Madonna and Guy Ritchie. The Coleherne public house in Earls Court was a well-known gay pub from the 1950s. It attracted many well-known patrons, such as Freddie Mercury, Kenny Everett and Rudolph Nureyev. It was used by the serial-killer Colin Ireland to pick up victims.
Document 7: Kensington Roof Gardens: The building housed the department store Derry and Toms until 1973, and then Biba until 1975. Since the 1980s the garden has been used as a restaurant and club.
Document 8: New Delhi: At the heart of the city is the magnificent Rashtrapati Bhavan (formerly known as Viceroy's House) which sits atop Raisina Hill. The Secretariat, which houses ministries of the Government of India, flanks out of the Rashtrapati Bhavan. The Parliament House, designed by Herbert Baker, is located at the Sansad Marg, which runs parallel to the Rajpath. Connaught Place is a large, circular commercial area in New Delhi, modelled after the Royal Crescent in England. Twelve separate roads lead out of the outer ring of Connaught Place, one of them being the Janpath.
Document 9: London: In 1762, George III acquired Buckingham House and it was enlarged over the next 75 years. During the 18th century, London was dogged by crime, and the Bow Street Runners were established in 1750 as a professional police force. In total, more than 200 offences were punishable by death, including petty theft. Most children born in the city died before reaching their third birthday. The coffeehouse became a popular place to debate ideas, with growing literacy and the development of the printing press making news widely available; and Fleet Street became the centre of the British press.
Document 10: Department store: All major cities have their distinctive local department stores, which anchored the downtown shopping district until the arrival of the malls in the 1960s. Washington, for example, after 1887 had Woodward & Lothrop and Garfinckel's starting in 1905. Garfield's went bankrupt in 1990, as did Woodward & Lothrop in 1994. Baltimore had four major department stores: Hutzler's was the prestige leader, followed by Hecht's, Hochschild's and Stewart's. They all operated branches in the suburbs, but all closed in the late twentieth century. By 2015, most locally owned department stores around the country had been consolidated into larger chains, or had closed down entirely.
Document 11: Pub: Many of London's pubs are known to have been used by famous people, but in some cases, such as the association between Samuel Johnson and Ye Olde Cheshire Cheese, this is speculative, based on little more than the fact that the person is known to have lived nearby. However, Charles Dickens is known to have visited the Cheshire Cheese, the Prospect of Whitby, Ye Olde Cock Tavern and many others. Samuel Pepys is also associated with the Prospect of Whitby and the Cock Tavern.
Document 12: Neues Schauspielhaus: While the auditorium was destroyed in World War II, the facade as well as the cinema survived and in 1951 was renamed the Metropol. Since 1977 it has been used as a discothèque and became a famous music club during the 1980s heyday of West Berlin, frequented by bands like Depeche Mode, Morrissey, The Cross, The Human League and Front 242. For a short time in 2000 it was the location of the KitKatClub and in 2005 the architect Hans Kollhoff remodeled the interior as the "Goya" night club.
Document 13: Department store: All the major British cities had flourishing department stores by the mid-or late nineteenth century. Increasingly, women became the major shoppers and middle-class households. Kendals (formerly Kendal Milne & Faulkner) in Manchester lays claim to being one of the first department stores and is still known to many of its customers as Kendal's, despite its 2005 name change to House of Fraser. The Manchester institution dates back to 1836 but had been trading as Watts Bazaar since 1796. At its zenith the store had buildings on both sides of Deansgate linked by a subterranean passage "Kendals Arcade" and an art nouveau tiled food hall. The store was especially known for its emphasis on quality and style over low prices giving it the nickname "the Harrods of the North", although this was due in part to Harrods acquiring the store in 1919. Other large Manchester stores included Paulden's (currently Debenhams) and Lewis's (now a Primark).
Document 14: Department store: The middle up segment is mainly occupied by Metro Department Store originated from Singapore and Sogo from Japan. 2007 saw the re-opening of Jakarta's Seibu, poised to be the largest and second most upscale department store in Indonesia after Harvey Nichols, which the latter closed in 2010 and yet plans to return. Other international department stores include Debenhams and Marks & Spencer. Galeries Lafayette also joins the Indonesian market in 2013 inside Pacific Place Mall. This department store is targeting middle up market with price range from affordable to luxury, poised to be the largest upscale department store. Galeries Lafayette, Debenhams, Harvey Nichols, Marks & Spencer, Seibu and Sogo are all operated by PT. Mitra Adiperkasa.
Document 15: Pub: The Angel, Islington was formerly a coaching inn, the first on the route northwards out of London, where Thomas Paine is believed to have written much of The Rights of Man. It was mentioned by Charles Dickens, became a Lyons Corner House, and is now a Co-operative Bank.
ground_truth: 1980s
sub_queries: Hansom Cab >> location Answer: Kensington
when did the roof gardens above Kensington open to the public Answer: 1980s