Year Percent 1996-01-01 19.988100000000000 1997-01-01 19.988100000000000 1998-01-01 20.910400000000000 1999-01-01 20.516600000000000 2000-01-01 47.567500000000000 2001-01-01 57.747600000000000 2002-01-01 60.761600000000000 2003-01-01 67.439500000000000 2004-01-01 22.605999999999998 2005-01-01 22.332500000000000 2006-01-01 26.016900000000000 2007-01-01 23.594200000000000 2008-01-01 20.840300000000000 2009-01-01 20.682700000000000 2010-01-01 19.988100000000000 2011-01-01 19.988100000000000 2012-01-01 19.988100000000000 2013-01-01 24.074300000000000 2014-01-01 25.359700000000000