Year Percent 1982-01-01 85.4727 1983-01-01 85.8517 1984-01-01 86.8623 1985-01-01 83.0165 1986-01-01 77.0876 1987-01-01 78.6274 1988-01-01 80.5524 1989-01-01 79.6919 1990-01-01 80.9730 1991-01-01 81.3264 1992-01-01 79.7440 1993-01-01 78.4949 1994-01-01 71.1242 1995-01-01 71.8281 1996-01-01 66.6324 1997-01-01 68.4852 1998-01-01 67.8649 1999-01-01 70.3234 2000-01-01 70.8594 2001-01-01 72.0534 2002-01-01 72.0577 2003-01-01 74.4994 2004-01-01 77.3120 2005-01-01 75.9695 2006-01-01 73.0358 2007-01-01 72.4883 2008-01-01 74.2763 2009-01-01 75.6871 2010-01-01 76.5317 2011-01-01 75.6352 2012-01-01 75.9942 2013-01-01 77.2027 2014-01-01 78.0043 2015-01-01 82.1536 2016-01-01 83.6148