Year Percent 1992-01-01 17.483400000000000 1993-01-01 16.188900000000000 1994-01-01 6.997719999999999 1995-01-01 6.951320000000000 1996-01-01 6.020610000000000 1997-01-01 5.972230000000001 1998-01-01 6.654260000000001 1999-01-01 7.486739999999999 2000-01-01 9.001890000000000 2001-01-01 10.530000000000000 2002-01-01 13.364700000000000 2003-01-01 17.741300000000000 2004-01-01 19.866500000000000 2005-01-01 23.581300000000000 2006-01-01 27.658000000000000 2007-01-01 29.969500000000000 2008-01-01 32.887900000000000 2009-01-01 36.919100000000000 2010-01-01 34.303300000000000 2011-01-01 35.168500000000000 2012-01-01 37.594500000000000 2013-01-01 41.991100000000000 2014-01-01 42.337300000000000 2015-01-01 38.991000000000000 2016-01-01 31.266000000000000