Students celebrate their A-level results at King Edward VI High School for Girls in Birmingham, England on August 18, 2016. The proportion of top grades achieved by A-level students across the UK has fallen for a fifth year in a row, and girls have caught up with boys in attaining A* grades. (Photo by Joe Giddens/PA Wire)

A boy shoots a World War II machine gun armed with blanks at an weapon exhibition during a military show near Kirovsk, about 30 kilometers (19 miles) east of St. Petersburg, Russia, Sunday, January 21, 2018. (Photo by Dmitri Lovetsky/AP Photo)

Jimmy Arnold, an overweight boy from Rochester, bites into a cake. (Photo by Reg Birkett/Keystone/Getty Images). 14th April 1951

A fish jumps over a net as a boy works in a fish farm at Htantapin township, outside Yangon, Myanmar February 18, 2016. One in five children in Myanmar aged 10-17 go to work instead of school, according to figures from a census report on employment published last month, and the opening up of the economy since 2011 has triggered a spike in demand for labour. Many children work in fish farming and processing. At Yangon's San Pya fish market, the country's largest, girls and boys as young as nine clean and process fish and unload boats and trucks during 12-hour overnight shifts. (Photo by Soe Zeya Tun/Reuters)

Afghan boys attend their Quran study sessions at the Islami Noor religious school on May 12, 2011 in Kandahar, Afghanistan. Despite recent multiple attacks near the city's downtown, children continue their studies at the school. (Photo by Majid Saeedi/Getty Images)

Tony Appleton, a town crier, announces the royal birth outside the Lindo Wing of St Mary's Hospital after Catherine, Duchess of Cambridge gave birth to a baby boy in central London July 22, 2013. Prince William's wife Kate gave birth on Monday to a baby boy, in the Lindo Wing of St Mary's Hospital, who becomes third in line to the British throne, his office said. The royal baby, the couple's first child, was born at 4:24 p.m. (15:24 GMT), weighing 8 lbs and 6 oz. (Photo by Lefteris Pitarakis/Associated Press)

A boy does a bicycle kick as he practises on the Marina beach ahead of the World Cup soccer tournament in Brazil, in Chennai June 4, 2014. REUTERS/Babu