Question: What was the July 2017 net worth of the incumbent mayor of New York in 2013

full_context: Document 1: Black billionaires: According to Forbes 2014 ranking of the world's billionaires, Nigerian business magnate Aliko Dangote with a net worth of $25 billion is the world's richest black person. Others on the list are Nigeria's Mike Adenuga with $4.6 billion, American media mogul Oprah Winfrey with a net worth of $3.9 billion (2015) and South African gold magnate Patrice Motsepe, with $2.9 billion, Nigeria's Folorunsho Alakija with $2.5 billion and Mo Ibrahim, a British billionaire of Sudanese Nubian ancestry, who has been on the "Forbes" Billionaire list since 2008 and in 2012 had a net worth of $1.1 billion.
Document 2: San Francisco mayoral election, 2003: The 2003 San Francisco mayoral election occurred on November 4, 2003. The incumbent, Willie Brown, was termed out of office and could not seek a third term. The general election included three top candidates including then Supervisor Gavin Newsom and then President of the Board of Supervisors, Matt Gonzalez and former Supervisor Angela Alioto. No candidate received the required majority so the race went into a run-off of the two top candidates, which were Gavin Newsom and Matt Gonzalez. The run-off occurred on December 9, 2003 where Gavin Newsom was elected mayor of San Francisco.
Document 3: Rochester mayoral election, 2013: The Rochester Mayoral Election of 2013 took place on November 5, 2011 in the City of Rochester, New York, United States. Democratic Mayor Thomas Richards, who first took office following Robert Duffy's resignation to take office of Lieutenant-Governor of New York in 2011, ran for reelection and was defeated in both the Democratic Primary and the general election by former City Council President Lovely A. Warren. Green Party candidate Alex White also ran and received a notable 5% of the vote. Considered a major upset victory, Lovely Warren defeated the incumbent mayor Richards in their party's primary against most major polling predictions.
Document 4: New York City mayoral election, 2013: The 2013 New York City mayoral election occurred on November 5, 2013, along with elections for comptroller, public advocate, borough presidents, and members of the New York City Council. The incumbent Mayor of New York, Michael Bloomberg, a Republican-turned-Independent, was term-limited and thus unable to seek re-election to a fourth term in office.
Document 5: George Soros: George Soros ( or ; Hungarian: "Soros György" , ] ; born György Schwartz, August 12, 1930) is a Hungarian-American investor, business magnate, philanthropist, and author. Soros is one of the world's most successful investors. As of May 2017, he had a net worth of $25.2 billion, ranking among the 30 richest people in the world.
Document 6: Bloomberg Distinguished Professorships: Bloomberg Distinguished Professorships (BDPs) were established as part of a $350 million gift by Michael Bloomberg, JHU Class of 1964, to Johns Hopkins University in 2013. Fifty faculty members, ten from Johns Hopkins University and forty recruited from institutions worldwide, will be chosen for these endowed professorships based on their research, teaching, service, and leadership records. The program is directed and managed by Johns Hopkins University Vice Provost for Research, Dr. Denis Wirtz.
Document 7: Paul Allen: Paul Gardner Allen (born January 21, 1953) is an American business magnate, investor and philanthropist. He is known for co-founding Microsoft alongside Bill Gates. As of June 2017, he is estimated to be the 46th richest person in the world, with an estimated net worth of $20.7 billion.
Document 8: New York City mayoral election, 2009: The 2009 election for Mayor of New York City took place on Tuesday, November 3. The incumbent Mayor, Michael Bloomberg, an independent who left the Republican Party in 2008, won reelection on the Republican and Independence Party/Jobs & Education lines with 50.7% of the vote over the retiring City Comptroller, Bill Thompson, a Democrat (also endorsed by the Working Families Party), who won 46.3%. Thompson had won the Democratic primary election on September 15 with 71% of the vote over City Councilman Tony Avella and Roland Rogers. This was the fifth straight mayoral victory by Republican candidates in New York despite the city's strongly Democratic leaning in national and state elections.
Document 9: Philadelphia mayoral election, 2007: The 2007 Philadelphia mayoral election was held on November 6, 2007 when Philadelphia, Pennsylvania, United States elected Michael Nutter as the Mayor of Philadelphia starting in 2008. The incumbent mayor, John F. Street was barred from seeking a third term because of term limits. The Democratic Party primary campaign saw two well-known, well-funded Philadelphia congressmen – Bob Brady and Chaka Fattah – eclipsed by self-funding businessman Tom Knox and reformist former Philadelphia City Council member Nutter, who won by a surprisingly large margin in the primary election on May 15. He went on to face Republican Party nominee Al Taubenberger in the general election, which he won by a large margin and with the lowest voter turnout in a Philadelphia mayoral election without an incumbent since 1951. Mayor Nutter was sworn in on January 7, 2008.
Document 10: New York Comptroller election, 2014: The 2014 New York Comptroller election took place on November 4, 2014, to elect the New York State Comptroller. Incumbent Democratic Comptroller Thomas DiNapoli was re-elected to a second full term in office.
Document 11: Buffalo mayoral election, 2013: The 2013 election for Mayor of Buffalo, New York took place on November 5, 2013. Two-term incumbent Mayor Byron Brown, a Democrat, faced Republican challenger Sergio Rodriguez.
Document 12: Newark mayoral election, 2014: The 2014 Newark mayoral election took place in Newark, the most populous city in New Jersey, USA, on May 13, 2014. The race was characterized as a contest between two candidates, Ras J. Baraka and Shavar Jeffries, both from Newark's South Ward. Elections for all seats on the nine member Municipal Council of Newark also took place. Luis A. Quintana, who had become Mayor of Newark following the resignation of Cory Booker, did not seek the seat.
Document 13: Rubin Schron: Rubin Schron, who goes by Ruby, is a New York City real estate investor, landlord and the founder of Cammeby's International Group. He has a personal net worth of well over $10 billion, according to data company Real Capital Analytics. The portfolio of Cammeby's, which Schron founded in 1967, includes office buildings, market-rate and government-subsidized apartment complexes, nursing homes, the 16-building complex in Sunset Park now known as Industry City, a stake in the bottom half of Woolworth Building and industrial properties scattered across Long Island. In 2013, Schron made an unsolicited and unsuccessful offer to buy the Empire State Building for $2 billion, but he has not had problems closing many other deals throughout his long career. In 2003, an investment group led by Schron paid $600 million for a portfolio of about 6,000 outer-borough apartments from Donald Trump. Other buildings he owns include the Monterey, a 521-unit rental multifamily building on Manhattan's Upper East Side; over the decades, Schron has also amassed a portfolio of Mitchell-Lama apartment buildings whose values have been skyrocketing to record values, after reverting to market rates when government subsidies expired. In 2007, he sold nearly 4,000 units of former Mitchell-Lama properties in five complexes in Harlem and on Roosevelt Island for $940 million. Schron, who practices Orthodox Judaism, has eight children and 50 grandchildren. He and his family have lived in the same single-family home in Brooklyn for many decades.
Document 14: Michael Bloomberg: Michael Rubens "Mike" Bloomberg (born February 14, 1942) is an American businessman, author, politician, and philanthropist. His net worth is estimated at US$ 53.4 billion, as of July 2017, ranking him as the 6th richest person in the United States and the 10th richest person in the world. He has joined The Giving Pledge, whereby billionaires pledge to give away at least half of their wealth.
Document 15: Bill Gates: William Henry Gates III (born October 28, 1955) is a co-founder of the Microsoft Corporation and is an American business magnate, investor, author and philanthropist.
ground_truth: 53.4 billion