A Humboldt penguin stands on weighing scales whilst being photographed by members of the press during a photocall at the annual weigh-in at London Zoo in London, Britain, 24 August 2016. Every animal that is in the zoo is weighed and measured and the statistics recorded so the data can be shared with zoos across the world. (Photo by Hannah McKay/EPA)

Manuela (L) and Marta, members of the Revolutionary Armed Forces of Colombia (FARC), pose for a picture at a camp in the Colombian mountains on February 18, 2016. Many of these women are willing to be reunited with the children they gave birth and then left under protection of relatives or farmers, whenever the peace agreement will put an end to the country's internal conflict. (Photo by Luis Acosta/AFP Photo)

Ernie Lotinga, looking terrified as a gun is pointed in his face, in a scene from the play “My Wife's Family”, at the Garrick Theatre, London. (Photo by Sasha/Getty Images). 24th February 1941

A young man “painting” the Eiffel Tower. (Photo by Keystone/Getty Images). 9th May 1970

A Chinese vendor wears a rooster hat as he smokes a cigarette at his souvenir stall at a fair at Temple of Earth, on the eve of Chinese New Year February 8, 2005 in Beijing, China. Chinese started February 8, to celebrate the New Year of the Rooster. (Photo by Andrew Wong/Getty Images)

Two children jumping through a water hydrant's shower on a New York street. They have come from a neighbouring co-educational playgroup organised by the city's Police Department. (Photo by Orlando/Getty Images). 1950

More than 400 people stripped off and ran into freezing waters to celebrate the autumn equinox – and raise money for charity at Druridge Bay, Britain, September 25, 2016. It was the largest turnout the North East Skinny Dip has ever seen in its five-year history, and it was also the first time it has ever rained on the morning of the event. Revellers gathered from 5.30am on Sunday at Druridge Bay, in Northumberland, before baring all in the North Sea. (Photo by David Charlton Photography)

An Omani woman prepares for a traditional dance during a ceremony attended by Britain's Prince Charles and his wife, Camilla, Duchess of Cornwall in Muscat, Oman, Saturday, November 5, 2016. The royal couple have started a three-nation royal tour of the Gulf in Oman. (Photo by Kamran Jebreili/AP Photo)