Year Percent 1961-01-01 305.58799999999997 1962-01-01 77.56740000000000 1963-01-01 80.01840000000000 1964-01-01 106.44300000000000 1965-01-01 103.26799999999999 1966-01-01 97.58570000000000 1967-01-01 92.29620000000000 1968-01-01 86.11910000000000 1969-01-01 78.35830000000000 1970-01-01 73.79650000000000 1971-01-01 59.96240000000000 1972-01-01 51.45460000000000 1973-01-01 40.69240000000000 1974-01-01 43.60750000000000 1975-01-01 67.30030000000000 1976-01-01 79.00720000000000 1977-01-01 122.74300000000000 1978-01-01 143.47100000000000 1979-01-01 143.31000000000000 1980-01-01 162.40300000000000 1981-01-01 183.56099999999998 1982-01-01 208.58000000000000 1983-01-01 232.24000000000000 1984-01-01 245.23800000000000 1985-01-01 226.34500000000000 1986-01-01 196.52100000000000 1987-01-01 177.55100000000000 1988-01-01 161.79800000000000 1989-01-01 157.44400000000000 1990-01-01 152.12000000000000 1991-01-01 136.54800000000000 1992-01-01 132.39000000000000 1993-01-01 138.14100000000000 1994-01-01 143.59799999999998 1995-01-01 146.05800000000000 1996-01-01 144.51200000000000 1997-01-01 136.34600000000000 1998-01-01 127.68200000000000 1999-01-01 122.11900000000000 2000-01-01 122.32300000000000 2001-01-01 128.18500000000000 2002-01-01 131.45700000000000 2003-01-01 135.88700000000000 2004-01-01 138.36900000000000 2005-01-01 135.13100000000000 2006-01-01 133.43800000000000 2007-01-01 135.16700000000000 2008-01-01 138.59400000000000 2009-01-01 153.38600000000000 2010-01-01 169.18800000000000 2011-01-01 164.91099999999997 2012-01-01 160.46900000000000 2013-01-01 156.19799999999998 2014-01-01 153.40800000000000 2015-01-01 149.75600000000000 2016-01-01 146.76600000000000