Athlets run during the women's 3000 meter steeplechase at the International Athletics Meeting in Lucerne, Switzerland, 14 June 2016. (Photo by Alexandra Wey/EPA)

A worker applies colour to strings which will be used to fly kites, by a roadside in Ahmedabad, India, November 23, 2017. (Photo by Amit Dave/Reuters)

An Afghan man prepares tea for customers at a roadside tea shop on the outskirts of Jalalabad February 2, 2015. (Photo by Reuters/Parwiz)

A roadside ice-cream vendor waits for customers at a market in New Delhi, India, April 7, 2016. The Indian economy is characterized by the existence of a vast majority of informal or unorganized labor employment. (Photo by Altaf Qadri/AP Photo)

Yanelis Blanco, 24, center, dances with a group of friends at Santa Maria beach, about 15 miles from Havana. It is the closest beach to Havana. Others, from left to right are Jackson Miranda, 21, Dayan Suarez, 24, and Melisa Oliva, 15. The men in the group have a rap group together. The government is demolishing buildings all over the coast of East Havana and recovering and restoring beach dunes. (Photo by Sarah L. Voisin/The Washington Post)

People take part in the Classic Ride Rally in downtown Valencia, eastern Spain, 23 November 2014. Some hundred people on classic bikes from the 20's to the 70's participated in the rally. (Photo by Kai Foersterling/EPA)

A six-year-old acrobat performs on the opening of a tourist festival in Bozhou, Anhui province, China May 3, 2015. (Photo by Reuters/China Daily)

Boys walk home for lunch from school in the village of Kogelo, west of Kenya's capital Nairobi, July 16, 2015. U.S. President Barack Obama visits Kenya and Ethiopia later this month. His ancestral home of Kogelo is home to Sarah Hussein Obama, his step-grandmother. The Kenyan village, burial place of Obama's father, features an open-pit goldmine, a pork butcher's, a school named after their most famous son and outdoor market stalls. Villagers get around by motorbike taxi or on foot while a donkey-cart transports water. Children, some of them named Obama in honour of the President, walk to and from school together. (Photo by Thomas Mukoya/Reuters)