Year	Percent
1991-01-01	41.705800000000000
1992-01-01	41.769500000000000
1993-01-01	39.531600000000000
1994-01-01	36.673200000000000
1995-01-01	41.567700000000000
1996-01-01	43.373999999999995
1997-01-01	42.170000000000000
1998-01-01	40.823700000000000
1999-01-01	42.403600000000000
2000-01-01	42.962700000000000
2001-01-01	44.862800000000000
2002-01-01	48.382200000000000
2003-01-01	52.660700000000000
2004-01-01	51.646900000000000
2005-01-01	52.662600000000000
2006-01-01	54.347000000000000
2007-01-01	51.903900000000000
2008-01-01	53.232000000000000
2009-01-01	57.735200000000000
2010-01-01	57.978500000000000
2011-01-01	57.367500000000000
2012-01-01	60.131200000000000
2013-01-01	61.068600000000000
2014-01-01	61.599000000000000
2015-01-01	61.828700000000000