Naomi Campbell attends the Swarovski Fashionation at Palazzo Reale on June 7, 2011 in Milan, Italy. (Photo by Vittorio Zunino Celotto/Getty Images)

Catherine, Duchess of Cambridge speaks to soldiers as she arrives at Calgary Airport on July 7, 2011 in Calgary, Canada. (Photo by Chris Jackson/Getty Images)

People board a train at the West Railway Station on January 7, 2012 in Beijing, China. China's railways are bracing themselves as millions of migrant labourers are set to leave cities for their native villages to celebrate the Chinese New Year. (Photo by Lintao Zhang/Getty Images)

An older model Ford Mustang sits on cinder blocks with missing wheels near an abandoned apartment building in Detroit, Michigan January 7, 2015. Detroit, also known as the Motor City, is the historic hub of automobile manufacturing in the United States. A federal judge in December 2013 formally declared the city bankrupt but it won court approval to exit bankruptcy last November. Once the proud symbol of U.S. industrial strength, Detroit fell on hard times after decades of population loss, rampant debt and financial mismanagement left it struggling to provide basic services to residents. (Photo by Joshua Lott/Reuters)

Park Ji-soo of South Korea performs her contemporary variation during the final of the 43rd Prix de Lausanne at the Beaulieu Theatre in Lausanne February 7, 2015. The Prix de Lausanne is an annual international dance competition for dancers aged 15 to 18. A total of 67 participants from 18 countries were selected from 300 applicants to take part in this year's week-long competition, from which the jury has shortlisted 20 finalists to compete for Saturday's finals. Six of this year's finalists will be awarded a one-year all expenses paid scholarship at one of the Prix de Lausanne's partner schools or companies, among the most prestigious in the world. (Photo by Denis Balibouse/Reuters)

Actress with the Donbass Opera Theatre prepares to perform Eugene Onegin in Donetsk, Ukraine, Saturday, February 7, 2015. For the few dozen spectators that turn up, the weekly performances at the city's opera house serve as a respite from the war raging outside between Russian-backed separatists and Ukrainian government forces. (Photo by Petr David Josek/AP Photo)

A military police officer aims his gun to a demonstrator during a protest in Brasilia, Brazil, Tuesday, April 7, 2015. The officer had picked up a bottle that was thrown towards them but did not fire his gun and backed away. Thousands of workers have staged rallies in 12 cities across Brazil to protest against a proposed law that would allow companies to outsource their labor force. (Photo by Eraldo Peres/AP Photo)