Year Percent 1990-01-01 0.3294160000000000 1991-01-01 0.4268560000000000 1992-01-01 0.6640980000000000 1993-01-01 0.8220010000000000 1994-01-01 1.0538700000000000 1995-01-01 1.1235600000000001 1996-01-01 1.0805000000000000 1997-01-01 1.0937700000000001 1998-01-01 1.1657300000000000 1999-01-01 1.3350000000000000 2000-01-01 1.3869300000000000 2001-01-01 1.4476400000000000 2002-01-01 1.2877200000000000 2003-01-01 1.4787800000000000 2004-01-01 1.6964700000000001 2005-01-01 1.8933200000000001 2006-01-01 2.0729100000000000 2007-01-01 2.0855400000000000 2008-01-01 2.0270700000000000 2009-01-01 1.9935800000000000 2010-01-01 1.7175700000000000 2011-01-01 1.5701800000000000 2012-01-01 1.4471700000000000 2013-01-01 1.3454300000000000 2014-01-01 1.3111899999999999 2015-01-01 1.4348000000000000 2016-01-01 1.5048500000000000 2017-01-01 1.4434200000000001