Year Percent 1964-01-01 16.767100000000000 1965-01-01 16.026800000000000 1966-01-01 16.405000000000000 1967-01-01 18.868300000000000 1968-01-01 20.398100000000000 1969-01-01 21.499000000000002 1970-01-01 21.630500000000000 1971-01-01 24.161600000000000 1972-01-01 26.981300000000000 1973-01-01 26.919400000000000 1974-01-01 26.603500000000000 1975-01-01 27.135700000000000 1976-01-01 28.887700000000000 1977-01-01 31.028900000000000 1978-01-01 31.217500000000000 1979-01-01 30.179300000000000 1980-01-01 31.456300000000000 1981-01-01 32.758700000000000 1982-01-01 35.512500000000000 1983-01-01 40.942900000000000 1984-01-01 46.844200000000000 1985-01-01 51.600000000000000 1986-01-01 54.164100000000000 1987-01-01 54.988100000000000 1988-01-01 54.699100000000000 1989-01-01 56.704800000000000 1990-01-01 60.608500000000000 1991-01-01 65.542700000000000 1992-01-01 67.954900000000000 1993-01-01 71.384800000000000 1994-01-01 72.637200000000000 1995-01-01 72.244900000000000 1996-01-01 74.836200000000000 1997-01-01 84.760200000000000 1998-01-01 99.978700000000000 1999-01-01 101.594000000000000 2000-01-01 100.252000000000010 2001-01-01 101.491000000000000 2002-01-01 97.437800000000000 2003-01-01 96.777100000000000 2004-01-01 96.432700000000000 2005-01-01 92.903200000000000 2006-01-01 89.596700000000000 2007-01-01 85.677200000000000 2008-01-01 87.505300000000000 2009-01-01 91.728700000000000 2010-01-01 87.949600000000000 2011-01-01 92.917800000000000 2012-01-01 99.146900000000000 2013-01-01 109.055000000000000 2014-01-01 114.640000000000000 2015-01-01 115.008000000000000 2016-01-01 114.452000000000010