Year	Percent
1980-01-01	50.661700000000000
1981-01-01	52.674100000000000
1982-01-01	56.303999999999995
1983-01-01	60.468500000000000
1984-01-01	62.233100000000000
1985-01-01	63.116900000000000
1986-01-01	66.399600000000000
1987-01-01	64.200200000000000
1988-01-01	63.043600000000000
1989-01-01	61.188600000000000
1990-01-01	56.610600000000000
1991-01-01	55.955700000000000
1992-01-01	58.091200000000000
1993-01-01	62.010500000000000
1994-01-01	65.138700000000000
1995-01-01	68.699600000000000
1996-01-01	71.190600000000000
1997-01-01	24.109800000000000
1998-01-01	28.410800000000000
1999-01-01	34.673700000000000
2000-01-01	44.345600000000000
2001-01-01	40.830500000000000
2002-01-01	44.716100000000000
2003-01-01	52.694900000000000
2004-01-01	54.790100000000000
2005-01-01	56.296600000000000
2006-01-01	57.120300000000000
2007-01-01	56.304500000000000
2008-01-01	62.962300000000000
2009-01-01	73.586600000000000
2010-01-01	66.873100000000000
2011-01-01	70.973900000000000
2012-01-01	69.258600000000000
2013-01-01	64.213700000000000
2014-01-01	69.876800000000000
2015-01-01	57.820700000000000
2016-01-01	53.267500000000000