Since the upheaval in Syria began five years ago, as many as 250,000 people have been killed and millions have fled their homes. Here are five graphics that help explain the state of the crisis today.

Before the conflict began, Syria's population was about 22 million. With so may people affected, the crisis is the world's worst humanitarian emergency in decades.

The violence and dire living conditions for many of the displaced have put millions of children in grave danger.

Today, Syria produces more internally displaced people and refugees than any other country in the world, according to the United Nations.

The focus of the refugee crisis has largely been on Europe, where more than a million desperate people arrived last year. But far more of the displaced have remained in countries nearer to Syria.

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