Year Percent 1962-01-01 1.7549000000000000 1963-01-01 1.4703200000000000 1964-01-01 1.1513600000000000 1965-01-01 0.9547540000000001 1966-01-01 0.7950470000000001 1967-01-01 0.8048600000000000 1968-01-01 2.1079300000000000 1969-01-01 2.4113300000000000 1970-01-01 1.8832200000000001 1971-01-01 2.9597900000000004 1972-01-01 6.0247600000000000 1973-01-01 6.1003700000000000 1974-01-01 6.4809300000000000 1975-01-01 8.1079500000000000 1976-01-01 9.0902700000000000 1977-01-01 11.3180000000000000 1978-01-01 12.0442000000000000 1979-01-01 10.9847000000000000 1980-01-01 9.2695200000000000 1981-01-01 9.1154000000000000 1982-01-01 10.5791000000000000 1983-01-01 14.9900000000000000 1984-01-01 13.1241000000000000 1985-01-01 23.9329000000000000 1986-01-01 27.6466000000000000 1987-01-01 30.4382000000000000 1988-01-01 29.4811000000000000 1989-01-01 40.7597000000000000 1990-01-01 43.6553000000000000 1991-01-01 42.5917000000000000 1992-01-01 46.1563000000000000 1993-01-01 68.2368000000000000 1994-01-01 73.4287000000000000 1995-01-01 70.5813000000000000 1996-01-01 68.1023000000000000 1997-01-01 61.3866000000000000 1998-01-01 69.0572000000000000 1999-01-01 76.7408000000000000 2000-01-01 96.3551000000000000 2001-01-01 125.1770000000000000 2002-01-01 128.7550000000000000 2003-01-01 153.2370000000000000 2004-01-01 215.4659999999999800 2005-01-01 257.4950000000000000 2006-01-01 339.0430000000000000 2007-01-01 315.2800000000000000 2008-01-01 330.6000000000000000 2009-01-01 397.2040000000000000 2010-01-01 311.8800000000000000 2011-01-01 237.1660000000000000 2012-01-01 174.1600000000000000 2013-01-01 135.5710000000000000 2014-01-01 114.0310000000000000 2015-01-01 95.0641000000000000 2016-01-01 66.4250000000000000