Year Percent 1993-01-01 59.372200000000000 1994-01-01 59.928999999999995 1995-01-01 61.505300000000000 1996-01-01 60.910100000000000 1997-01-01 61.638900000000000 1998-01-01 58.086600000000000 1999-01-01 50.856400000000000 2000-01-01 45.133800000000000 2001-01-01 38.487100000000000 2002-01-01 30.833700000000000 2003-01-01 26.803000000000000 2004-01-01 27.540000000000000 2005-01-01 30.193200000000000 2006-01-01 34.341500000000000 2007-01-01 39.073700000000000 2008-01-01 45.922600000000000 2009-01-01 47.654600000000000 2010-01-01 46.047900000000000 2011-01-01 47.341300000000000 2012-01-01 49.585600000000000 2013-01-01 50.535800000000000 2014-01-01 49.315800000000000 2015-01-01 48.540600000000000 2016-01-01 49.722900000000000