Year Percent 1982-01-01 4.3089900000000005 1983-01-01 5.0941700000000000 1984-01-01 5.1020699999999990 1985-01-01 4.8721500000000000 1986-01-01 5.5384800000000000 1987-01-01 5.6746000000000000 1988-01-01 6.1468400000000000 1989-01-01 6.7424300000000010 1990-01-01 6.6051199999999990 1991-01-01 5.8286100000000000 1992-01-01 5.5552000000000000 1993-01-01 5.4149600000000000 1994-01-01 5.6120800000000010 1995-01-01 5.2168600000000000 1996-01-01 5.8587400000000000 1997-01-01 5.6331100000000000 1998-01-01 5.3707600000000000 1999-01-01 5.0145000000000000 2000-01-01 5.3441100000000000 2001-01-01 10.3979000000000000 2002-01-01 15.8596000000000000 2003-01-01 16.2486000000000000 2004-01-01 16.0393000000000000 2005-01-01 15.6662000000000000 2006-01-01 17.2221000000000000 2007-01-01 19.4633000000000000 2008-01-01 22.1258000000000000 2009-01-01 22.9325000000000000 2010-01-01 22.9583000000000000 2011-01-01 23.8780000000000000 2012-01-01 26.6971000000000000 2013-01-01 26.6770000000000000 2014-01-01 29.7796000000000000 2015-01-01 30.4873000000000000 2016-01-01 34.6921000000000000