Year Percent 1993-01-01 15.395500000000000 1994-01-01 17.198700000000000 1995-01-01 10.639900000000000 1996-01-01 5.785630000000000 1997-01-01 5.775640000000000 1998-01-01 6.905660000000001 1999-01-01 7.690860000000001 2000-01-01 10.207800000000000 2001-01-01 14.707700000000000 2002-01-01 18.851500000000000 2003-01-01 21.183200000000000 2004-01-01 24.067500000000000 2005-01-01 29.876400000000000 2006-01-01 38.642400000000000 2007-01-01 48.328200000000000 2008-01-01 50.374100000000000 2009-01-01 50.872900000000000 2010-01-01 43.430700000000000 2011-01-01 37.984400000000000 2012-01-01 38.717200000000000 2013-01-01 37.433400000000000 2014-01-01 37.125300000000000 2015-01-01 35.952400000000000 2016-01-01 33.316400000000000