further 7%, and gas by 9%, during 2011. Production declines of 6% annually under Repsol were reversed following the renationalization, however. Amid sharp increases in profitability and investment, output in 2013 rose by 3.4% in oil and a 2.2% in gas, and a further 8.7% and 12.5% in oil and gas, respectively, during 2014. YPF announced the discovery in November 2011 of an 8071 km2 unconventional oil field, Vaca Muerta, with recoverable reserves of 22.8 billion barrels of oil equivalent, and potential to extend to an area of up to 30,000 km2 (11,600 mi2). Its reserves of crude and natural gas, not including the new shale finds, fell 60% and 67% respectively between 1999 and 2011. The firm's new headquarters, the Repsol-YPF Tower, was designed by César Pelli and inaugurated in 2008. Company statistics Notes: unless specified. Three year periods are averages. Output data from 1995 to 2011 includes Maxus Energy and other overseas units, typically around 20% of YPF's worldwide total. Exchange rate from IMF.* excludes Maxus Energy. See also Enarsa Bridas YCF References External links Argentine brands Government-owned companies of Argentina Companies listed on the New York Stock Exchange Energy companies established in 1922 Argentina Companies listed on the Buenos Aires Stock Exchange Oil and gas companies of Argentina Argentine companies established in 1922 Companies based in Buenos Aires Non-renewable resource companies established in 1922