Query: Immigrants arriving by sea are coming mainly for what reason?
Context: In 2012, the majority of illegal immigrants entering Greece came from Afghanistan, followed by Pakistanis and Bangladeshis. In 2015, arrivals of refugees by sea have increased dramatically mainly due to the ongoing Syrian civil war. There were 856,723 arrivals by sea in Greece, an almost fivefold increase to the same period of 2014, of which the Syrians represent almost 45%.