Year Percent 1990-01-01 0.051275000000000000 1991-01-01 0.056774000000000000 1992-01-01 0.056655000000000000 1993-01-01 0.058147000000000004 1994-01-01 0.047028000000000000 1995-01-01 0.042408000000000000 1996-01-01 0.044556000000000000 1997-01-01 0.051611000000000004 1998-01-01 0.059095000000000000 1999-01-01 0.066643000000000000 2000-01-01 0.060861000000000000 2001-01-01 0.062258000000000000 2002-01-01 0.065495000000000000 2003-01-01 0.077640000000000000 2004-01-01 0.085473000000000010 2005-01-01 0.085937000000000000 2006-01-01 0.091383000000000000 2007-01-01 0.095058000000000000 2008-01-01 0.105492000000000000 2009-01-01 0.119505000000000000 2010-01-01 0.129440000000000000 2011-01-01 0.130905000000000000 2012-01-01 0.143451000000000000 2013-01-01 0.157994000000000000 2014-01-01 0.143157999999999980 2015-01-01 0.131764000000000020