Year Percent 1989-01-01 12.403100000000000 1990-01-01 12.584900000000000 1991-01-01 14.950700000000000 1992-01-01 15.819500000000000 1993-01-01 15.640999999999998 1994-01-01 14.822300000000000 1995-01-01 14.900500000000000 1996-01-01 15.080800000000000 1997-01-01 12.859600000000000 1998-01-01 20.322800000000000 1999-01-01 24.525300000000000 2000-01-01 25.784400000000000 2001-01-01 32.664500000000000 2002-01-01 36.320300000000000 2003-01-01 38.101500000000000 2004-01-01 38.677000000000000 2005-01-01 36.481200000000000 2006-01-01 37.583900000000000 2007-01-01 37.028700000000000 2008-01-01 37.346500000000000 2009-01-01 45.840600000000000 2010-01-01 42.878500000000000 2011-01-01 37.884400000000000 2012-01-01 39.670800000000000 2013-01-01 32.366200000000000 2014-01-01 24.107200000000000 2015-01-01 25.214900000000000 2016-01-01 25.522300000000000