2000 attended a welcome party at TigerTiger Manchester which was the first event in set of big club night for new students to Manchester and Salford universities in Manchester, UK on September 19, 2016. This year, university bosses have stepped up security in Manchester. (Photo by Jordan Sinclair/UK News Pictures)

People view the sunrise scene at the Bund in Shanghai, east China, January 1, 2017. (Photo by Wang Hechun/Xinhua/Barcroft Images)

A migrant carries his belongings as he arrives at the Beijing railway station to catch a train in Beijing, Friday, February 13, 2015. (Photo by Andy Wong/AP Photo)

An election poster calling for the legalisation of marijuana and featuring internet meme “Grumpy Cat” hangs outside the Pirate Party's campaign headquarters in Berlin on August 16, 2013. The Pirates, who to everyone's surprise were elected into Berlin's regional parliament in September 2011, are trying to capitalise on their recent electoral gains in upcoming parliamentary elections, running on a platform of transparency in government. Germany goes to the polls on September 22, 2013. Placard reads: “Hurry up, my dope is everything”. (Photo by John Macdougall/AFP Photo)

People eat sushi off the body of a model at an opening event of a bar in Taiyuan, Shanxi province, August 22, 2015. (Photo by Reuters/Stringer)

Three female friends dancing in nightclub. (Photo by Cultura Creative (RF)/Alamy Stock Photo )

Ethnic Uyghur tourists guides wait to perform in a show for Chinese tourists on June 29, 2017 in the old town of Kashgar, in the far western Xinjiang province, China. Kashgar has long been considered the cultural heart of Xinjiang for the province's nearly 10 million Muslim Uyghurs. (Photo by Kevin Frayer/Getty Images)

A painting of a Trabant car bursting through a wall in post unification Berlin, August 1993. (Photo by Steve Eason/Hulton Archive/Getty Images)