A man carries a bag on his back in Guangzhou, Guangdong province, January 26, 2016. According to traffic police, over 2.9 billion trips will be made around China during the 40-day Spring Festival travel rush, which started on January 24. (Photo by Reuters/Stringer)

A Pakistani vendor tries to salvage materials after flood water destroyed his shop following heavy rain on the outskirts of Peshawar on April 4, 2016. (Photo by A. Majeed/AFP Photo)

Zulmira Jesus poses for a portrait at a street in Povoa de Agracoes, near Chaves, Portugal April 19, 2016. In the villages of Agracoes and Povoa de Agracoe, the steady drip-drip of emigration has brought down population numbers from more than 50 residents to fewer than a dozen each. These remaining villagers share the same glum acceptance that, after they have gone, their villages will die out too. It is the same desolate picture in scores of other backwater settlements in Portugal's interior, north to south. (Photo by Rafael Marchante/Reuters)

Gas-masked men of the British Machine Gun Corps with a Vickers machine gun during the first battle of the Somme, 1916. (Photo by General Photographic Agency/Getty Images)

Many of the 12 million people who entered the US through New York’s Ellis Island wore traditional dress from their homelands. Here: A Ruthenian woman circa 1906 from the region historically inhabiting the kingdom of the Rus, incorporating parts of modern-day Slavic speaking countries. Her outfit consists of a shirt and underskirt made from linen embroidered with traditional floral-based patterns. (Photo by Augustus Francis Sherman/New York Public Library/The Guardian)

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

A quartet of showgirls in costume sit at an outdoor table and drink from mugs at Disneyland amusement park, Anaheim, California, 1955. (Photo by Loomis Dean/The LIFE Picture Collection/Getty Images)

A vendor (C) serves customers at a vegetable market as a commuter train passes in Jakarta October 2, 2015. Indonesia's high annual inflation rate cooled in September and should drop more by year-end, but it likely will be 2016 before the central bank can cut interest rates to help an economy growing at its slowest pace in six years. (Photo by Reuters/Beawiharta)