Year Percent 1960-01-01 206.34599999999998 1961-01-01 199.46700000000000 1962-01-01 195.56099999999998 1963-01-01 161.61500000000000 1964-01-01 157.77900000000000 1965-01-01 145.80100000000002 1966-01-01 117.08700000000000 1967-01-01 121.31600000000000 1968-01-01 134.08900000000000 1969-01-01 131.24000000000000 1970-01-01 115.51500000000000 1971-01-01 107.11100000000000 1972-01-01 97.91210000000000 1973-01-01 90.80840000000000 1974-01-01 84.74860000000000 1975-01-01 92.31580000000000 1976-01-01 103.38900000000000 1977-01-01 89.67780000000000 1978-01-01 80.76050000000000 1979-01-01 82.86290000000000 1980-01-01 82.80280000000000 1981-01-01 82.35080000000000 1982-01-01 83.63460000000000 1983-01-01 77.80430000000000 1984-01-01 72.53399999999999 1985-01-01 60.02650000000000 1986-01-01 54.13960000000000 1987-01-01 59.11790000000000 1988-01-01 59.88040000000000 1989-01-01 53.07680000000000 1990-01-01 46.33610000000000 1991-01-01 49.15660000000000 1992-01-01 41.11160000000000 1993-01-01 30.53290000000000 1994-01-01 31.83880000000000 1995-01-01 34.94330000000000 1996-01-01 38.74430000000000 1997-01-01 44.16880000000000 1998-01-01 38.81100000000000 1999-01-01 33.84810000000000 2000-01-01 34.51470000000000 2001-01-01 37.68380000000000 2002-01-01 44.48880000000000 2003-01-01 55.35820000000000 2004-01-01 63.49110000000000 2005-01-01 68.61330000000000 2006-01-01 78.07860000000000 2007-01-01 85.41420000000000 2008-01-01 83.39350000000000 2009-01-01 79.50790000000000 2010-01-01 75.19660000000000 2011-01-01 71.61480000000000 2012-01-01 69.72360000000000 2013-01-01 71.72130000000000 2014-01-01 71.52580000000000 2015-01-01 66.73850000000000