Year Percent 1996-01-01 1.8549900000000001 1997-01-01 2.9160200000000000 1998-01-01 5.3902199999999990 1999-01-01 6.3507400000000000 2000-01-01 8.4259200000000000 2001-01-01 8.7202000000000000 2002-01-01 9.2240200000000000 2003-01-01 8.8687800000000010 2004-01-01 7.6129500000000000 2005-01-01 4.6393200000000000 2006-01-01 4.7507800000000010 2007-01-01 7.8677300000000000 2008-01-01 9.1775300000000000 2009-01-01 15.6079999999999990 2010-01-01 16.5243000000000000 2011-01-01 14.6990000000000020 2012-01-01 15.7411000000000000 2013-01-01 23.4250000000000000 2014-01-01 35.4231000000000000 2015-01-01 36.4628000000000000 2016-01-01 33.7130000000000000