Dubai has emerged as a global city and business hub of the Middle East.[6] It is also a major transport hub for passengers and cargo. By the 1960s, Dubai's economy was based on revenues from trade and, to a smaller extent, oil exploration concessions, but oil was not discovered until 1966. Oil revenue first started to flow in 1969.[7] Dubai's oil revenue helped accelerate the early development of the city, but its reserves are limited and production levels are low: today, less than 5% of the emirate's revenue comes from oil.[8] The emirate's Western-style model of business drives its economy with the main revenues now coming from tourism, aviation, real estate, and financial services.[9][10][11] Dubai has recently attracted world attention through many innovative large construction projects and sports events. The city has become iconic for its skyscrapers and high-rise buildings, in particular the world's tallest building, the Burj Khalifa. Dubai has been criticised for human rights violations concerning the city's largely South Asian workforce.[12] Dubai's property market experienced a major deterioration in 2008–09 following the financial crisis of 2007–08,[13] but the emirate's economy has made a return to growth, with a projected 2015 budget surplus.[14]