Year Percent 1993-01-01 51.6382 1994-01-01 43.0428 1995-01-01 35.0388 1996-01-01 37.1025 1997-01-01 46.1009 1998-01-01 51.5138 1999-01-01 52.0351 2000-01-01 50.5113 2001-01-01 42.6526 2002-01-01 36.4274 2003-01-01 33.6727 2004-01-01 29.0294 2005-01-01 30.6774 2006-01-01 34.6171 2007-01-01 33.7932 2008-01-01 37.8512 2009-01-01 44.2671 2010-01-01 43.8465 2011-01-01 45.3506 2012-01-01 46.4494 2013-01-01 47.1357 2014-01-01 48.3940 2015-01-01 50.7785 2016-01-01 54.3179