Year Percent 1960-01-01 52.66500000000000 1961-01-01 49.74030000000000 1962-01-01 51.19550000000000 1963-01-01 52.25270000000000 1964-01-01 54.26120000000000 1965-01-01 57.13890000000000 1966-01-01 56.58340000000000 1967-01-01 57.62020000000000 1968-01-01 59.93350000000000 1969-01-01 61.45960000000000 1970-01-01 63.83670000000000 1971-01-01 68.20570000000000 1972-01-01 71.55460000000000 1973-01-01 73.11030000000000 1974-01-01 72.08440000000000 1975-01-01 73.80370000000000 1976-01-01 73.40420000000000 1977-01-01 69.70800000000000 1978-01-01 66.98180000000000 1979-01-01 67.81490000000000 1980-01-01 68.94660000000000 1981-01-01 71.21410000000000 1982-01-01 72.09190000000000 1983-01-01 66.88810000000000 1984-01-01 59.93650000000000 1985-01-01 58.49500000000000 1986-01-01 61.62350000000000 1987-01-01 64.02300000000000 1988-01-01 62.98760000000000 1989-01-01 62.93470000000000 1990-01-01 64.04730000000000 1991-01-01 66.58380000000000 1992-01-01 67.55360000000000 1993-01-01 69.64520000000000 1994-01-01 71.09210000000000 1995-01-01 70.70410000000000 1996-01-01 69.47430000000000 1997-01-01 66.33500000000000 1998-01-01 67.94290000000000 1999-01-01 75.33370000000000 2000-01-01 84.72760000000000 2001-01-01 86.77310000000000 2002-01-01 84.52040000000000 2003-01-01 83.85410000000000 2004-01-01 83.71880000000000 2005-01-01 84.44920000000000 2006-01-01 87.00340000000000 2007-01-01 89.92540000000000 2008-01-01 100.42500000000000 2009-01-01 109.84299999999999 2010-01-01 108.74200000000000 2011-01-01 106.54500000000000 2012-01-01 106.44800000000000 2013-01-01 107.32300000000000 2014-01-01 107.76299999999999 2015-01-01 108.36200000000001 2016-01-01 109.75000000000000