Year Percent 1980-01-01 5.20765 1981-01-01 5.38235 1982-01-01 6.23725 1983-01-01 6.02779 1984-01-01 5.38891 1985-01-01 4.30105 1986-01-01 4.21052 1987-01-01 4.04019 1988-01-01 5.36605 1989-01-01 5.63729 1990-01-01 7.16178 1991-01-01 8.30280 1992-01-01 8.23343 1993-01-01 10.47840 1994-01-01 8.75863 1995-01-01 8.58686 1996-01-01 8.47824 1997-01-01 8.77383 1998-01-01 10.94610 1999-01-01 10.74590 2000-01-01 9.16784 2001-01-01 9.61077 2002-01-01 10.77030 2003-01-01 12.00550 2004-01-01 11.38080 2005-01-01 11.39860 2006-01-01 10.87430 2007-01-01 10.58420 2008-01-01 14.55260 2009-01-01 16.43900 2010-01-01 20.22860 2011-01-01 20.10330 2012-01-01 19.74990 2013-01-01 23.10020 2014-01-01 22.67420 2015-01-01 24.87490 2016-01-01 25.68840