Year	Percent
1999-01-01	4.24875522064951
2000-01-01	4.26453505500495
2001-01-01	3.89557508858598
2002-01-01	3.41493049369490
2003-01-01	3.52350500658846
2004-01-01	4.05809083466696
2005-01-01	3.74328461082002
2006-01-01	3.37694655207027
2007-01-01	2.45229287798112
2008-01-01	2.00911839756386
2009-01-01	3.40062206257672
2010-01-01	3.69342433310866
2011-01-01	3.31757512288115
2012-01-01	3.44884259016823
2013-01-01	3.39168286111027