Year Percent 1990-01-01 6.740800000000000 1991-01-01 4.869210000000000 1992-01-01 5.265030000000000 1993-01-01 6.543870000000000 1994-01-01 7.791480000000000 1995-01-01 8.310330000000000 1996-01-01 7.520020000000000 1997-01-01 7.396180000000000 1998-01-01 8.097680000000000 1999-01-01 9.600800000000000 2000-01-01 10.888900000000000 2001-01-01 10.741600000000000 2002-01-01 13.164400000000000 2003-01-01 20.756999999999998 2004-01-01 22.830100000000000 2005-01-01 25.149100000000000 2006-01-01 26.730400000000000 2007-01-01 23.508400000000000 2008-01-01 18.086300000000000 2009-01-01 20.073500000000000 2010-01-01 15.925900000000000 2011-01-01 13.247000000000000 2012-01-01 11.409800000000000 2013-01-01 10.135400000000000 2014-01-01 11.928400000000000 2015-01-01 13.072600000000000 2016-01-01 16.404400000000000