Year Percent 1990-01-01 27.9465 1991-01-01 30.1179 1992-01-01 32.9443 1993-01-01 35.3705 1994-01-01 36.6319 1995-01-01 36.9941 1996-01-01 37.5226 1997-01-01 29.6611 1998-01-01 45.9516 1999-01-01 60.3533 2000-01-01 50.7187 2001-01-01 53.9559 2002-01-01 66.1627 2003-01-01 58.6034 2004-01-01 62.4206 2005-01-01 56.1694 2006-01-01 57.2202 2007-01-01 55.0652 2008-01-01 47.7618 2009-01-01 71.7533 2010-01-01 65.4993 2011-01-01 61.3757 2012-01-01 71.0821 2013-01-01 72.5874 2014-01-01 67.5039 2015-01-01 66.9193 2016-01-01 64.0794