Year Percent 1962-01-01 24.693700000000000 1963-01-01 26.045700000000000 1964-01-01 25.844600000000000 1965-01-01 28.016000000000000 1966-01-01 30.509400000000000 1967-01-01 32.578000000000000 1968-01-01 37.224000000000004 1969-01-01 38.700700000000000 1970-01-01 36.306000000000000 1971-01-01 28.390000000000000 1972-01-01 33.738900000000000 1973-01-01 31.873000000000000 1974-01-01 19.671200000000000 1975-01-01 23.615900000000000 1976-01-01 26.531100000000000 1977-01-01 33.950900000000000 1978-01-01 40.787600000000000 1979-01-01 31.014300000000000 1980-01-01 33.152600000000000 1981-01-01 49.000400000000000 1982-01-01 69.404200000000000 1983-01-01 77.729700000000000 1984-01-01 78.007100000000000 1985-01-01 79.422700000000000 1986-01-01 98.128900000000000 1987-01-01 83.166300000000000 1988-01-01 93.966900000000000 1989-01-01 80.753000000000000 1990-01-01 80.753000000000000 1991-01-01 191.187000000000000 1992-01-01 103.573000000000000 1993-01-01 85.623900000000000 1994-01-01 88.217800000000000 1995-01-01 86.340500000000000 1996-01-01 78.406800000000000 1997-01-01 80.924500000000000 1998-01-01 94.899700000000000 1999-01-01 82.590200000000000 2000-01-01 67.878300000000000 2001-01-01 80.474800000000000 2002-01-01 80.845300000000000 2003-01-01 70.193200000000000 2004-01-01 62.543400000000000 2005-01-01 52.358300000000000 2006-01-01 48.603100000000000 2007-01-01 52.812600000000000 2008-01-01 52.031900000000000 2009-01-01 76.362400000000000 2010-01-01 76.442200000000000 2011-01-01 62.815700000000000 2012-01-01 58.577700000000000 2013-01-01 62.457700000000000 2014-01-01 71.105500000000000 2015-01-01 98.330700000000000 2016-01-01 103.923999999999990