Year Percent 1980-01-01 0.6195520000000000 1981-01-01 0.8226020000000000 1982-01-01 1.2606000000000000 1983-01-01 1.5644900000000000 1984-01-01 2.2378299999999998 1985-01-01 3.4139900000000000 1986-01-01 3.2593700000000000 1987-01-01 3.8186500000000000 1988-01-01 3.8776800000000002 1989-01-01 4.1377500000000000 1990-01-01 4.2542000000000000 1991-01-01 5.1106300000000005 1992-01-01 4.5308699999999990 1993-01-01 6.8785500000000000 1994-01-01 8.5026500000000000 1995-01-01 9.4295900000000000 1996-01-01 9.2048700000000000 1997-01-01 10.5750000000000000 1998-01-01 12.2798000000000000 1999-01-01 15.6745000000000000 2000-01-01 21.7577000000000000 2001-01-01 27.1744000000000000 2002-01-01 30.6780000000000000 2003-01-01 33.1941000000000000 2004-01-01 36.0235000000000000 2005-01-01 34.3823000000000000 2006-01-01 41.5916000000000000 2007-01-01 45.0889000000000000 2008-01-01 44.9405000000000000 2009-01-01 55.5172000000000000 2010-01-01 54.8278000000000000 2011-01-01 50.4965000000000000 2012-01-01 53.4549000000000000 2013-01-01 54.7176000000000000 2014-01-01 46.5061000000000000 2015-01-01 48.3773000000000000 2016-01-01 44.4700000000000000