Year Percent 1960-01-01 12.8240000000000020 1961-01-01 12.7790000000000020 1962-01-01 10.4922000000000000 1963-01-01 8.5884500000000000 1964-01-01 5.8293099999999995 1965-01-01 5.3960900000000000 1966-01-01 5.7354199999999995 1967-01-01 5.8635900000000000 1968-01-01 4.9631700000000000 1969-01-01 5.1962100000000000 1970-01-01 6.1963700000000000 1971-01-01 8.8189800000000000 1972-01-01 11.0247000000000000 1973-01-01 11.0212000000000000 1974-01-01 9.4644000000000000 1975-01-01 12.6919000000000000 1976-01-01 11.4984000000000000 1977-01-01 12.8278000000000000 1978-01-01 15.5076000000000000 1979-01-01 11.9671000000000000 1980-01-01 11.9671000000000000 1981-01-01 11.9671000000000000 1982-01-01 11.9671000000000000 1983-01-01 11.9671000000000000 1984-01-01 11.9671000000000000 1985-01-01 11.9671000000000000 1986-01-01 11.9671000000000000 1987-01-01 11.9671000000000000 1988-01-01 11.9671000000000000 1989-01-01 11.9671000000000000 1990-01-01 11.9671000000000000 1991-01-01 11.9671000000000000 1992-01-01 11.9671000000000000 1993-01-01 11.9671000000000000 1994-01-01 11.9671000000000000 1995-01-01 11.9671000000000000 1996-01-01 11.9671000000000000 1997-01-01 11.9671000000000000 1998-01-01 11.9671000000000000 1999-01-01 11.9671000000000000 2000-01-01 37.5818000000000000 2001-01-01 32.5950000000000000 2002-01-01 24.7323000000000000 2003-01-01 22.7183000000000000 2004-01-01 20.6933000000000000 2005-01-01 18.4432000000000000 2006-01-01 17.4346000000000000 2007-01-01 19.8197000000000000 2008-01-01 29.3453000000000000 2009-01-01 52.9232000000000000 2010-01-01 41.2828000000000000 2011-01-01 98.1249000000000000 2012-01-01 41.7404000000000000 2013-01-01 75.4107000000000000 2014-01-01 75.4107000000000000 2015-01-01 203.8900000000000000 2016-01-01 197.8960000000000000