Year Percent 1990-01-01 0.022438999999999997 1991-01-01 0.077416000000000000 1992-01-01 0.096042999999999990 1993-01-01 0.098425000000000000 1994-01-01 0.098970000000000000 1995-01-01 0.101880000000000000 1996-01-01 0.190834000000000000 1997-01-01 0.105887000000000000 1998-01-01 0.122893000000000000 1999-01-01 0.152586000000000000 2000-01-01 0.193968000000000000 2001-01-01 0.241323999999999980 2002-01-01 0.278764000000000000 2003-01-01 0.288790000000000000 2004-01-01 0.275821000000000000 2005-01-01 0.270474000000000000 2006-01-01 0.243761999999999980 2007-01-01 0.228948000000000000 2008-01-01 0.206154000000000000 2009-01-01 0.218480999999999980 2010-01-01 0.220379000000000000 2011-01-01 0.199345000000000000 2012-01-01 0.193922000000000000 2013-01-01 0.193640000000000000 2014-01-01 0.195068000000000020 2015-01-01 0.207638000000000020