Year Percent 1999-01-01 6.602110000000001 2000-01-01 7.990150000000000 2001-01-01 8.237230000000000 2002-01-01 8.863590000000000 2003-01-01 8.844900000000000 2004-01-01 8.322750000000000 2005-01-01 6.788030000000000 2006-01-01 8.251339999999999 2007-01-01 9.764110000000000 2008-01-01 9.993660000000000 2009-01-01 24.977400000000000 2010-01-01 30.721100000000000 2011-01-01 28.195900000000000 2012-01-01 32.773200000000000 2013-01-01 43.722100000000000 2014-01-01 55.388200000000000 2015-01-01 57.934600000000000 2016-01-01 48.268500000000000