Year Percent 1989-01-01 4.978540000000000 1990-01-01 4.978540000000000 1991-01-01 4.978540000000000 1992-01-01 14.370700000000000 1993-01-01 11.103600000000000 1994-01-01 8.544010000000000 1995-01-01 8.478890000000000 1996-01-01 7.969480000000000 1997-01-01 9.282210000000001 1998-01-01 10.464700000000000 1999-01-01 11.537900000000000 2000-01-01 14.628700000000000 2001-01-01 13.078100000000000 2002-01-01 13.047000000000000 2003-01-01 13.999700000000000 2004-01-01 13.632600000000000 2005-01-01 15.088400000000000 2006-01-01 18.393200000000000 2007-01-01 17.111100000000000 2008-01-01 20.100200000000000 2009-01-01 26.182900000000000 2010-01-01 29.980700000000000 2011-01-01 31.614600000000000 2012-01-01 32.868400000000000 2013-01-01 37.374100000000000 2014-01-01 43.288500000000000 2015-01-01 46.602600000000000 2016-01-01 46.899200000000000