Year Percent 1994-01-01 4.0758000000000000 1995-01-01 3.2198300000000000 1996-01-01 2.9924000000000000 1997-01-01 2.9986099999999998 1998-01-01 3.6134400000000000 1999-01-01 4.3598200000000000 2000-01-01 4.1454900000000010 2001-01-01 4.1445300000000005 2002-01-01 5.7845100000000000 2003-01-01 7.2731800000000000 2004-01-01 12.5363000000000000 2005-01-01 15.0974000000000000 2006-01-01 22.8053000000000000 2007-01-01 25.7148000000000000 2008-01-01 24.2400000000000000 2009-01-01 28.9591000000000000 2010-01-01 25.7585000000000000 2011-01-01 19.5251000000000000 2012-01-01 18.8380000000000000 2013-01-01 16.5557000000000000 2014-01-01 16.9321000000000000 2015-01-01 15.4128000000000000 2016-01-01 19.3978000000000000