Year Percent 1996-01-01 26.007200000000000 1997-01-01 10.462000000000000 1998-01-01 8.932330000000000 1999-01-01 8.591339999999999 2000-01-01 8.622650000000000 2001-01-01 8.622650000000000 2002-01-01 8.622650000000000 2003-01-01 2.310740000000000 2004-01-01 9.930190000000000 2005-01-01 20.470600000000000 2006-01-01 19.574100000000000 2007-01-01 21.490900000000000 2008-01-01 15.000500000000000 2009-01-01 12.428300000000000 2010-01-01 15.473600000000000 2011-01-01 13.787600000000000 2012-01-01 9.885100000000000 2013-01-01 7.576919999999999 2014-01-01 7.011950000000000 2015-01-01 6.748080000000000 2016-01-01 8.467430000000000