Year Percent 1960-01-01 70.33970000000000 1961-01-01 71.68880000000000 1962-01-01 72.82710000000000 1963-01-01 75.84870000000000 1964-01-01 78.85230000000000 1965-01-01 81.38720000000000 1966-01-01 81.30680000000000 1967-01-01 82.85430000000000 1968-01-01 83.85420000000000 1969-01-01 84.15480000000000 1970-01-01 85.01010000000000 1971-01-01 85.76200000000000 1972-01-01 89.10870000000000 1973-01-01 90.27630000000000 1974-01-01 90.31510000000000 1975-01-01 87.53900000000000 1976-01-01 85.47180000000000 1977-01-01 85.94960000000000 1978-01-01 85.89350000000000 1979-01-01 87.77290000000000 1980-01-01 90.79840000000000 1981-01-01 87.33820000000000 1982-01-01 89.68360000000000 1983-01-01 90.62640000000000 1984-01-01 92.03090000000000 1985-01-01 96.85260000000000 1986-01-01 103.65500000000000 1987-01-01 108.53200000000001 1988-01-01 108.95400000000000 1989-01-01 111.73800000000000 1990-01-01 113.34600000000000 1991-01-01 115.12500000000000 1992-01-01 115.39100000000000 1993-01-01 116.81700000000001 1994-01-01 117.03900000000000 1995-01-01 122.56700000000001 1996-01-01 130.57000000000000 1997-01-01 138.00300000000000 1998-01-01 148.14300000000000 1999-01-01 159.89700000000002 2000-01-01 162.42000000000000 2001-01-01 164.89000000000000 2002-01-01 163.41899999999998 2003-01-01 165.00099999999998 2004-01-01 173.80900000000003 2005-01-01 178.74800000000000 2006-01-01 185.18900000000002 2007-01-01 192.82100000000000 2008-01-01 195.57900000000000 2009-01-01 188.73300000000000 2010-01-01 180.04000000000000 2011-01-01 175.30700000000002 2012-01-01 170.92800000000000 2013-01-01 176.85100000000000 2014-01-01 182.15200000000002 2015-01-01 178.87700000000000 2016-01-01 179.01200000000000