That is according to the (London) Telegraph.
The link is HERE.
The Telegraph does not say it, but everyone should understand that that 20% will be on the balance young and poor, and hence angry. That, historically speaking, has always been the recipe for an attempted coup or revolution or civil war or something of the sort (think American Revolution, French Revolution, Bolshevik Revolution, etc.)
Ultimately though, it's hard to feel sorry for the (white) Europeans. The Islamization of Europe is a sure thing unless we are treated to another one of those fascinating European concoctions like Communism, Marxism, Nazism, fascism, or ultra-nationalism. I doubt that it will happen though--those all were led and initiated by youth, and Europe has successfully birth-controlled and aborted its youth away.
So long Europe.