Passengers travel on the London train and underground system during the Christmas party season, December 18, 2015. (Photo by Paul Hackett/Reuters)

People are reflected on a soap bubble lying on a road during the evening in New Delhi, India, June 23, 2015. (Photo by Anindito Mukherjee/Reuters)

A rickshaw man runs under the blooming cherry blossoms in Tokyo, Sunday, March 29, 2015. (Photo by Shizuo Kambayashi/AP Photo)

A stuntman performs while riding a car inside the “Wall of Death” attraction during a fair in Bhaktapur April 20, 2015. (Photo by Navesh Chitrakar/Reuters)

Turkish artist Nezaket Ekici performs a live art performance entitled 'Emotion in Motion' on the first day of Art Basel 2015, Hong Kong, China, 13 March 2015. The Hong Kong show of Art Basel features 233 galleries from 37 countries and territories, presenting works ranging from the Modern period of the early 20th century to the most contemporary artists of today, according to the official press release. (Photo by Alex Hofford/EPA)

A cloud of black smoke billows out the exhaust pipe of John Robertson's diesel dragster as he runs down the track during the 2015 NHRA Kansas Nationals, Friday, May 22, 2015, at Heartland Park in Topeka, Kan. (Photo by Chris Neal/The Topeka Capital-Journal via AP Photo)

In this photo taken on Sunday, July 5, 2015, police officers walk along a giant poster to give an improved appearance, in downtown Ufa, Russia. Ufa will host SOC (Shanghai Cooperation Organization) and BRICS (Brazil, Russia, India, China and South Africa) summits July 7 to July 9, 2015. (Photo by Vadim Braydov/AP Photo)