Year Percent 1994-01-01 18.555800000000000 1995-01-01 20.341700000000000 1996-01-01 25.783400000000000 1997-01-01 36.843000000000000 1998-01-01 39.078100000000000 1999-01-01 42.543100000000000 2000-01-01 42.635500000000000 2001-01-01 42.982100000000000 2002-01-01 44.693800000000000 2003-01-01 43.495300000000000 2004-01-01 45.760600000000000 2005-01-01 48.627400000000000 2006-01-01 52.662600000000000 2007-01-01 56.795700000000000 2008-01-01 56.568999999999996 2009-01-01 55.674000000000000 2010-01-01 57.951600000000000 2011-01-01 63.978600000000000 2012-01-01 67.897900000000000 2013-01-01 69.680900000000000 2014-01-01 69.333200000000000 2015-01-01 69.050800000000000 2016-01-01 67.760000000000000