Year Percent 1993-01-01 57.9853 1994-01-01 50.7412 1995-01-01 45.5992 1996-01-01 49.5091 1997-01-01 59.8596 1998-01-01 64.4770 1999-01-01 62.1605 2000-01-01 60.6706 2001-01-01 62.9069 2002-01-01 62.8950 2003-01-01 56.5939 2004-01-01 49.7503 2005-01-01 49.5371 2006-01-01 50.3981 2007-01-01 47.4113 2008-01-01 50.8992 2009-01-01 60.8779 2010-01-01 62.3672 2011-01-01 63.1179 2012-01-01 63.7233 2013-01-01 63.8996 2014-01-01 63.7844 2015-01-01 65.3521 2016-01-01 67.7003