Refugee crisis: apart from Syrians, who is travelling to Europe?

Syrians account for 50% of the 380,000 refugees who had arrived in Europe after crossing the Mediterranean by early September, but several other nationalities are turning up in large numbers. So apart from Syria, where are they coming from, why did they leave, and how are they reaching Europe?
http://www.theguardian.com/world/2015/sep/10/refugee-crisis-apart-from-syrians-who-else-is-travelling-to-europe