The Red Arrows make a flypast during the Trooping The Colour parade at Buckingham Palace, in London, Saturday, June 13, 2015. Hundreds of soldiers in ceremonial dress have marched in London in the annual Trooping the Color parade to mark the official birthday of Queen Elizabeth II. The Trooping the Color tradition originates from preparations for battle, when flags were carried or "trooped" down the rank for soldiers to see. (AP Photo/Tim Ireland)

Students from St Andrew's University indulge in a tradition of covering themselves with foam to honour the “academic family” on October 20, 2014, in St Andrews, Scotland. Every November the “raisin weekend” which is held in the university's Lower College Lawn, is celebrated and a gift of raisins (now foam) is traditionally given by first year students to their elders as a thank you for their guidance and in exchange they receive a receipt in Latin. (Photo by Jeff J. Mitchell/Getty Images)

A passenger waits after his train arrived in Nouadhibou, Mauritania’s second largest city and the main export port for the country’s iron ore industry, on June 25, 2014. The mining company’s employees proudly call their firm the lung of their nation's economy and the train that ferries the ore to the coast stretches some two kilometres, making it one of the world's longest. SNIM mines black iron ore in the northern town of Zouerate, a remote desert location which nevertheless attracts people from all over the country looking for work. (Photo by Joe Penney/Reuters)

A man tries to stop two bulls from locking horns during a bullfight in the eastern emirate of Fujairah October 17, 2014. There are no matadors or picadors, but bulls locking horns with each other draw big crowds to bullfights in the United Arab Emirates (UAE). An hour's drive from the dancing water fountains of Dubai's glitzy downtown, hundreds of fans gather in Fujairah to watch bulls fighting, or perhaps more accurately head butting, with honour rather than money at stake. The UAE sport involves two bulls locking horns in a three-to-four minute Sumo-wrestling-like fight that usually ends with no bloodshed. (Photo by Ahmed Jadallah/Reuters)

People walk under stands with balloons placed along the former Berlin Wall location at Mauerpark, which will be used in the installation “Lichtgrenze” (Border of Light) in Berlin November 7, 2014. A part of the inner city of Berlin will be temporarily divided from November 7 to 9, with a light installation featuring 8000 luminous white balloons to commemorate the 25th anniversary of the fall of the Berlin Wall. (Photo by Pawel Kopczynski/Reuters)

Abigail Crouse lifts her Thor hammer high after running through Sleeping Beauty's Castle during the Avengers Super Heroes Half Marathon in and around the Disney Parks in Anaheim, California November 16, 2014. Walt Disney Co has moved aggressively into the race business, attracting tens of thousands of runners every year to its marathons, half-marathons and family-friendly races. (Photo by Eugene Garcia/Reuters)

An aerial view of open pits of CODELCO's Andina (L) and Anglo American's Los Bronces copper mines with Olivares glaciers in the background (top L) at Los Andes Mountain range, near Santiago city, November 17, 2014. The rock glaciers of the Chilean central zone, a huge source of water for the basins of the capital, are said to be threatened by the environmental impacts of hydroelectric and mining projects, according to environmental activists Greenpeace. (Photo by Ivan Alvarado/Reuters)