Question: Shanghai Tower is the world's third-tallest structure behind a building that reached its full height in which year ?
Context: Tokyo Skytree (東京スカイツリー , Tōkyō Sukaitsurī ) is a broadcasting, restaurant, and observation tower in Sumida, Tokyo, Japan.  It became the tallest structure in Japan in 2010 and reached its full height of 634.0 m in March 2011, making it the tallest tower in the world, displacing the Canton Tower, and the second tallest structure in the world after the Burj Khalifa (829.8 m/2,722 ft). The Canton Tower, or Guangzhou Tower (), formally Guangzhou TV Astronomical and Sightseeing Tower (), is a 604 m tall multi-purpose observation tower in the Haizhu District of Guangzhou (historically known as Canton or Kwangchow), Guangdong, China.  The tower was topped out in 2009 and it became operational on 29 September 2010 for the 2010 Asian Games.  The tower briefly held the title of tallest tower in the world, replacing the CN Tower, before being surpassed by the Tokyo Skytree.  It was the tallest structure in China prior to the topping out of Shanghai Tower on 3 August 2013.  It is now the second tallest tower and the fourth-tallest freestanding structure in the world. The KVLY-TV mast (formerly the KTHI-TV mast) is a 2,063 ft (628.8 m) tall television-transmitting mast in Blanchard, Traill County, North Dakota, United States, used by Fargo station KVLY-TV channel 11.  Completed in 1963, it was the tallest structure in the world until succeeded by the Warsaw radio mast in 1974, which collapsed in 1991, again making the KVLY-TV mast the tallest structure in the world until the Burj Khalifa overtook it in 2010.  It remains the fourth-tallest structure in the world (since the construction of the Tokyo Skytree and the Shanghai Tower), the tallest structure in the western hemisphere, and the tallest radio mast in the world. Superman: Escape from Krypton (originally known as Superman: The Escape) is a steel shuttle roller coaster located at Six Flags Magic Mountain in Valencia, California.  When it opened in 1997, it was the tallest roller coaster in the world, and its speed of 100 mph was tied for the fastest with Tower of Terror II, a similar roller coaster which opened two months earlier at Dreamworld in Australia.  These two coasters were the first to utilize Linear Synchronous Motor (LSM) technology to propel vehicles to top speed.  The park originally intended to open the ride in 1996, but the opening was delayed because of several issues with the launch system.  The ride was closed in late 2010 for refurbishment, and it emerged in 2011 as "Superman: Escape from Krypton".  The refurbished ride featured new trains which face backward, and it was painted with a new color scheme.  As of 2013, Superman: Escape from Krypton has the third-tallest structure, the fifth-fastest speed and the third-longest drop in the world. The Shanghai Tower () is a 632 m , 128-story megatall skyscraper in Lujiazui, Pudong, Shanghai.  As of 2015, it is the world's tallest building, by height to highest usable floor (Level 127, 587.4 m).  It also has the world's highest observation deck within a building or structure (Level 121, 561.25 m), and the world's fastest elevators at a top speed of 20.5 m/s (74 km/h; 46 mph ).  It is the world's second-tallest building by height to architectural top (behind Dubai's Burj Khalifa, 828 m) and the world's third-tallest structure (behind Tokyo Skytree, 634 m). The Jin Mao Tower (), also known as the Jinmao Building or Jinmao Tower , is an 88-story (93 if counting the floors in the spire) landmark skyscraper in Lujiazui, Pudong, Shanghai, China.  It is 420.5 m tall and is one of the tallest buildings in the world.  It contains a shopping mall, offices and the Grand Hyatt Shanghai hotel, which at the time of completion was the highest hotel in the world.  Along with the Oriental Pearl Tower, the Shanghai World Financial Center and the Shanghai Tower it is part of the Lujiazui skyline seen from the Bund.  It was the tallest building in China from its completion in 1999 until 2007, when it was surpassed by the Shanghai World Financial Center which is located close by.  The Shanghai Tower, a 121-story building located next to these two buildings, surpassed the height of both these buildings in 2015. The Romeo and Juliet Windmill, is a wooden structure designed by architect Frank Lloyd Wright in the town of Wyoming, Wisconsin (Wyoming is south of the town of Spring Green).  It was designed in 1896 after being commissioned by Wright's aunts, Jane and Ellen Lloyd Jones, who needed the windmill to provide water for their school, the Hillside Home School.  The diamond-shaped portion of the windmill intersects the portion with the balcony that sits on an octagonal structure.  The balcony is accessible through an interior stairway.  Wright named these two parts of the building "Romeo" and "Juliet".  "Romeo" is the lozenge and Juliet, the octagon.  Architectural historian, Neil Levine explained the principles behind the lozenge and octagon: [Wright] gave the tower a bold geometric form as a structural solution to the expression of the tower's role as a landmark.  The pump rod and support for the wheel are carried up within an acutely angled lozenge shape pointed southeast to deflect blasts of wind like a "storm prow".  This angular element is inserted halfway into a larger octagonal volume that contains and supports it throughout nearly its full height.  Wright called the composition Romeo and Juliet, likening its conjugate geometry to an amorous union. Shanghai Tower is a proposed 50-storey skyscraper, to be built as part of the multibillion-pound Liverpool Waters development in Liverpool, England.  The proposal pays homage to Shanghai in China, which is a sister city of Liverpool.  As of 2017 Shanghai tower was not included in the scheme central docks master plan. Wuhan Greenland Center is a 636 m 125-storey skyscraper currently under construction in Wuhan, China.  In June 2011, Adrian Smith + Gordon Gill Architects in conjunction with Thornton Tomasetti Engineers won the design competition to build the tower for Greenland Group.  The design has many energy saving features.  The building's height was increased to 636 m , and is expected to become the tallest building in China, surpassing Shanghai Tower.  The expected completion date is 2018. Tokyo is the most populated of Japan's 47 prefectures.  In Tokyo, there are 46 buildings and structures that stand taller than 185 metres (607 ft).  The tallest structure in the prefecture is Tokyo Skytree, a lattice tower that rises 634 metres (2,080 ft), which was completed in 2012.  It also stands as the tallest structure in Japan, the tallest tower in the world and the 2nd-tallest freestanding structure in the world.  The tallest building and third-tallest overall structure in Tokyo is the 256-metre-tall (838 ft) Toranomon Hills, which was completed in 2014.  The prefecture's second tallest building is Midtown Tower, which rises 54 stories and 248 metres (814 ft) in height.  Overall, of the 25 tallest buildings and structures in Japan, 16 are in Tokyo.
Answer: 2011