Year Percent 1990-01-01 2.851610000000000 1991-01-01 6.093369999999999 1992-01-01 9.829950000000000 1993-01-01 12.738100000000000 1994-01-01 14.156500000000000 1995-01-01 16.868400000000000 1996-01-01 17.525500000000000 1997-01-01 16.755500000000000 1998-01-01 15.403600000000000 1999-01-01 13.249300000000000 2000-01-01 9.887650000000000 2001-01-01 11.277700000000000 2002-01-01 11.284900000000000 2003-01-01 12.040200000000000 2004-01-01 17.546500000000000 2005-01-01 34.027100000000000 2006-01-01 32.760300000000000 2007-01-01 40.209000000000000 2008-01-01 40.827900000000000 2009-01-01 47.458600000000000 2010-01-01 64.418700000000000 2011-01-01 62.341900000000000 2012-01-01 63.794500000000000 2013-01-01 60.167400000000000 2014-01-01 44.797500000000000 2015-01-01 33.389800000000000 2016-01-01 32.700700000000000 2017-01-01 37.354200000000000