A Uyghur boy sits atop a horse as he has his picture taken outside the Id Kah Mosque before the Eid holiday on July 28, 2014 in old Kashgar, Xinjiang Province, China. Nearly 100 people have been killed in unrest in the restive Xinjiang Province in the last week in what authorities say is terrorism but advocacy groups claim is a result of a government crackdown to silence opposition to its policies. China's Muslim Uyghur ethnic group faces cultural and religious restrictions by the Chinese government. Beijing says it is investing heavily in the Xinjiang region but Uyghurs are increasingly dissatisfied with the influx of Han Chinese and uneven economic development. (Photo by Kevin Frayer/Getty Images)

In this Thursday, May 8, 2014 photo, Iranian coal miners push metal carts to be loaded with coal at a mine near the city of Zirab 212 kilometers (132 miles) northeast of the capital Tehran, on a mountain in Mazandaran province, Iran. International sanctions linked to the decade-long dispute over Iran's nuclear program have hindered the import of heavy machinery and modern technology in all sectors, and coal mining is no exception. (Photo by Ebrahim Noroozi/AP Photo)

Artist Le Pustra and organiser Else Edelstahl pose for a picture at Simon Dach Strasse, a street filled with many bars, in Berlin, Germany, August 28, 2016. Else Edelstahl organises the party series “Boheme Sauvage”, in which people dress up in 1920s style, celebrating Berlin nightlife of a past era. (Photo by Hannibal Hanschke/Reuters)

China has recently relaxed its one child policy that was used to control a burgeoning population. A couple has their wedding photo taken in an old quarter of Beijing on May 24, 2016. (Photo by Michael Robinson Chavez/The Washington Post)

Santa Jerry Julian of Colorado Springs, Colorado hides in the grass following a ride on the Polar Express during a field trip from the Charles W. Howard Santa Claus School in Midland, Michigan, U.S. October 28, 2016. (Photo by Christinne Muschi/Reuters)

A protester throws a stone towards a burning police bus in front of him, during clashes with police, in central Kiev, Ukraine, Sunday, January 19, 2014. Hundreds of protesters on Sunday clashed with riot police in the center of the Ukrainian capital, after the passage of harsh anti-protest legislation last week seen as part of attempts to quash anti-government demonstrations. The violent scenes further escalated this ex-Soviet republic's political crisis and showed a rift among opposition leaders, one of whom fought bravely to stop the violence, while others condemned the events from afar. (Photo by Evgeny Feldman/AP Photo)

A woman sits with a Great Dane during the first day of the Crufts dog show in Birmingham, central England March 6, 2014. (Photo by Darren Staples/Reuters)

A Naga man carries fish in his teeth after it was stunned by dynamite, which fishermen threw in a creek between Donhe and Lahe township, in the Naga Self-Administered Zone in northwest Myanmar December 27, 2014. (Photo by Soe Zeya Tun/Reuters)