Year Percent 1990-01-01 4.697440000000000 1991-01-01 4.715120000000000 1992-01-01 6.249650000000000 1993-01-01 7.720470000000000 1994-01-01 8.602150000000000 1995-01-01 8.733889999999999 1996-01-01 10.157100000000000 1997-01-01 11.190000000000000 1998-01-01 9.911030000000000 1999-01-01 12.857500000000000 2000-01-01 15.466700000000000 2001-01-01 26.802700000000000 2002-01-01 34.698400000000000 2003-01-01 43.648000000000000 2004-01-01 39.505000000000000 2005-01-01 34.826400000000000 2006-01-01 30.898200000000000 2007-01-01 31.116200000000000 2008-01-01 22.448600000000000 2009-01-01 32.906300000000000 2010-01-01 28.956500000000000 2011-01-01 22.185400000000000 2012-01-01 24.034300000000000 2013-01-01 19.173200000000000 2014-01-01 18.591100000000000 2015-01-01 16.961500000000000 2016-01-01 14.811400000000000