Year Percent 1973-01-01 56.38390000000000 1974-01-01 51.11910000000000 1975-01-01 42.50760000000000 1976-01-01 34.36560000000000 1977-01-01 31.26460000000000 1978-01-01 27.57290000000000 1979-01-01 25.97290000000000 1980-01-01 27.49550000000000 1981-01-01 30.89310000000000 1982-01-01 34.26850000000000 1983-01-01 40.70370000000000 1984-01-01 46.65430000000000 1985-01-01 50.27420000000000 1986-01-01 53.38890000000000 1987-01-01 57.83750000000000 1988-01-01 63.21360000000000 1989-01-01 68.59590000000000 1990-01-01 75.18010000000000 1991-01-01 80.14399999999999 1992-01-01 83.16960000000000 1993-01-01 90.11340000000000 1994-01-01 94.46880000000000 1995-01-01 90.56840000000000 1996-01-01 98.58610000000000 1997-01-01 106.53500000000000 1998-01-01 113.99100000000000 1999-01-01 122.07900000000000 2000-01-01 123.89399999999999 2001-01-01 131.28900000000000 2002-01-01 131.96000000000000 2003-01-01 125.12100000000001 2004-01-01 126.64200000000001 2005-01-01 124.73200000000001 2006-01-01 125.08800000000000 2007-01-01 125.70400000000000 2008-01-01 130.34300000000000 2009-01-01 144.51300000000000 2010-01-01 143.94200000000000 2011-01-01 145.34900000000000 2012-01-01 141.51100000000000 2013-01-01 132.15100000000000 2014-01-01 121.53399999999999 2015-01-01 110.80500000000000 2016-01-01 102.79700000000001