Year Percent 1996-01-01 0.41050000000000000 1997-01-01 0.45196300000000000 1998-01-01 0.34635900000000003 1999-01-01 0.31513700000000000 2000-01-01 0.44275400000000000 2001-01-01 5.86973000000000100 2002-01-01 7.23101000000000000 2003-01-01 8.19002000000000000 2004-01-01 6.63676999999999900 2005-01-01 5.44230000000000000 2006-01-01 5.02909000000000000 2007-01-01 3.81331999999999960 2008-01-01 3.52634000000000030 2009-01-01 3.06796000000000000 2010-01-01 2.63369000000000000 2011-01-01 2.58313000000000000 2012-01-01 2.68794000000000000 2013-01-01 2.98959000000000000 2014-01-01 2.96965000000000000 2015-01-01 2.97762000000000000 2016-01-01 3.12837000000000000 2017-01-01 3.88038000000000000