Year Percent 1988-01-01 111.5640 1989-01-01 39.1550 1990-01-01 44.2601 1991-01-01 86.8990 1992-01-01 67.9147 1993-01-01 56.7835 1994-01-01 49.0256 1995-01-01 52.0965 1996-01-01 59.2949 1997-01-01 71.3649 1998-01-01 78.7421 1999-01-01 80.6359 2000-01-01 75.6622 2001-01-01 66.6477 2002-01-01 56.3458 2003-01-01 48.9800 2004-01-01 43.9526 2005-01-01 46.4015 2006-01-01 53.8401 2007-01-01 51.8109 2008-01-01 56.4324 2009-01-01 66.6491 2010-01-01 71.2847 2011-01-01 71.2654 2012-01-01 66.4073 2013-01-01 66.9083 2014-01-01 70.8269 2015-01-01 69.8185 2016-01-01 69.8798