Year Percent 1992-01-01 21.694600000000000 1993-01-01 20.396300000000000 1994-01-01 9.438690000000000 1995-01-01 10.020500000000000 1996-01-01 10.299000000000001 1997-01-01 11.353600000000000 1998-01-01 12.751300000000000 1999-01-01 13.629100000000000 2000-01-01 15.583100000000000 2001-01-01 18.233900000000000 2002-01-01 23.136500000000000 2003-01-01 28.525800000000000 2004-01-01 30.311700000000000 2005-01-01 34.865100000000000 2006-01-01 39.522600000000000 2007-01-01 42.040400000000000 2008-01-01 38.713000000000000 2009-01-01 35.634700000000000 2010-01-01 33.048800000000000 2011-01-01 33.788200000000000 2012-01-01 36.249200000000000 2013-01-01 40.578400000000000 2014-01-01 40.740000000000000 2015-01-01 37.426000000000000 2016-01-01 30.171500000000000