Year Percent 1960-01-01 84.85060000000000 1961-01-01 87.22470000000000 1962-01-01 90.55440000000000 1963-01-01 91.74480000000000 1964-01-01 92.20850000000000 1965-01-01 91.18080000000000 1966-01-01 91.27420000000000 1967-01-01 91.86920000000000 1968-01-01 89.52090000000000 1969-01-01 89.21660000000000 1970-01-01 88.69100000000000 1971-01-01 87.09600000000000 1972-01-01 87.49330000000000 1973-01-01 87.55590000000000 1974-01-01 88.05000000000000 1975-01-01 89.43680000000000 1976-01-01 82.51230000000000 1977-01-01 75.40880000000000 1978-01-01 73.65800000000000 1979-01-01 71.13310000000000 1980-01-01 70.92000000000000 1981-01-01 72.39080000000000 1982-01-01 73.32850000000000 1983-01-01 74.87630000000000 1984-01-01 77.91340000000000 1985-01-01 85.24950000000000 1986-01-01 101.53000000000000 1987-01-01 114.37400000000000 1988-01-01 116.16900000000000 1989-01-01 117.03600000000000 1990-01-01 116.03299999999999 1991-01-01 111.24200000000000 1992-01-01 103.37500000000000 1993-01-01 101.71100000000000 1994-01-01 103.58500000000000 1995-01-01 106.55500000000000 1996-01-01 113.00900000000000 1997-01-01 125.77500000000000 1998-01-01 133.20700000000000 1999-01-01 134.06100000000000 2000-01-01 139.85900000000000 2001-01-01 143.58900000000000 2002-01-01 143.28500000000000 2003-01-01 144.97000000000000 2004-01-01 149.26800000000000 2005-01-01 154.58800000000000 2006-01-01 159.33500000000000 2007-01-01 172.58900000000003 2008-01-01 192.48500000000000 2009-01-01 196.98200000000000 2010-01-01 194.31900000000002 2011-01-01 194.80900000000003 2012-01-01 193.44299999999998 2013-01-01 190.24200000000002 2014-01-01 186.82800000000000 2015-01-01 196.54400000000000 2016-01-01 201.09400000000002