Year Percent 1990-01-01 1.5112400000000000 1991-01-01 1.6751099999999999 1992-01-01 1.6943700000000002 1993-01-01 1.7355200000000002 1994-01-01 1.9256799999999998 1995-01-01 1.9697799999999999 1996-01-01 1.9253200000000001 1997-01-01 1.7948200000000000 1998-01-01 1.8000500000000000 1999-01-01 1.7957800000000000 2000-01-01 1.6731599999999998 2001-01-01 1.6335400000000000 2002-01-01 1.4958799999999999 2003-01-01 1.5027200000000000 2004-01-01 1.3890000000000000 2005-01-01 1.2844700000000000 2006-01-01 1.4312300000000000 2007-01-01 1.5686600000000000 2008-01-01 1.7144099999999998 2009-01-01 1.7278700000000000 2010-01-01 1.8306400000000000 2011-01-01 1.8665100000000000 2012-01-01 1.7158600000000000 2013-01-01 1.6641400000000002 2014-01-01 1.6100400000000000 2015-01-01 1.5535100000000000 2016-01-01 1.3443399999999999