Syria has experienced an extreme population growth, according to the official national population census and recent official estimates: 1970: 6,304,685, 1981: 9,052,628, 1994: 13,782,315, 2004: 17,920,844, 2009: 23,027,000, 2011: 24,504,000, respectively (Tabutin and Schoumaker 2005; MENA 2013). Added to that there were 486,946 Palestinian refugees in Syria as of December 31, 2011 (UNRWA 2013).