Year Percent 1980-01-01 3.0779400000000003 1981-01-01 3.9833500000000000 1982-01-01 4.2251300000000000 1983-01-01 4.5675099999999995 1984-01-01 5.1800300000000000 1985-01-01 6.4973000000000000 1986-01-01 6.5149099999999995 1987-01-01 8.0394399999999990 1988-01-01 9.1951800000000000 1989-01-01 10.9654000000000000 1990-01-01 9.5321199999999990 1991-01-01 8.6187899999999990 1992-01-01 7.5600100000000010 1993-01-01 5.7466400000000000 1994-01-01 6.0360600000000000 1995-01-01 5.6033400000000000 1996-01-01 5.5457800000000010 1997-01-01 5.9532700000000000 1998-01-01 6.7961899999999990 1999-01-01 7.3457200000000000 2000-01-01 8.6492399999999990 2001-01-01 10.6379000000000000 2002-01-01 11.9713000000000000 2003-01-01 15.9921000000000000 2004-01-01 17.5242000000000000 2005-01-01 21.2987000000000000 2006-01-01 27.0291000000000000 2007-01-01 35.0245000000000000 2008-01-01 36.0523000000000000 2009-01-01 47.0789000000000000 2010-01-01 42.9351000000000000 2011-01-01 40.0437000000000000 2012-01-01 46.6508000000000000 2013-01-01 44.3181000000000000 2014-01-01 38.7583000000000000 2015-01-01 44.3009000000000000 2016-01-01 44.4021000000000000