Traditional miners carry sulphur on the Ijen volcano complex on May 25, 2009 outside Banyuwangi, East Java, Indonesia. Miners carry the solidified yellow sulphur blocks from the crater floor to the rim for as many hours a day as they can tolerate, paid by the kilogram of sulphur they extract. The average wage is USD $.05 per kilogram of sulphur and a worker, depending on his strength and stamina, carry on average 3 baskets of 70-80kg per day, earning him around USD $11. (Photo by Ulet Ifansasti/Getty Images)

A couple ride a motorcycle along a street during snow in Altay, Xinjiang Uighur Autonomous Region, China, November 8, 2015. Picture taken November 8, 2015. (Photo by Reuters/Stringer)

A roadside currency exchange vendor sorts Indian currency notes at his stall in Agartala, India, December 6, 2016. (Photo by Jayanta Dey/Reuters)

An Iranian soldier guards two German tourists near the Iranian-Turkish border during World War II. Since the British occupation of Iran, all Axis nationals are being expelled from the country. (Photo by Three Lions/Getty Images). Circa 1941

The Pink Floyd inflatable pig floats next to Broadcasting House to promote their new exhibition at the V&A museum, in London, Britain May 10, 2017. (Photo by Neil Hall/Reuters)

A woman stands at the door of her shanty at a slum in Mumbai, India July 20, 2016. (Photo by Danish Ismail/Reuters)

Members of the Honour Guard and the central military band of the Mongolian armed forces perform during the International Military Music Festival “Spasskaya Tower” media preview in Red Square in Moscow, Russia, August 26, 2016. (Photo by Sergei Karpukhin/Reuters)

Commuters hang off a local passenger train in the morning in Colombo, Sri Lanka September 8, 2016. (Photo by Dinuka Liyanawatte/Reuters)