Year	Percent
1980-01-01	7.382639999999999
1981-01-01	3.892120000000000
1982-01-01	13.937200000000000
1983-01-01	14.555800000000000
1984-01-01	14.528700000000000
1985-01-01	13.889000000000001
1986-01-01	12.392300000000000
1987-01-01	12.761700000000000
1988-01-01	11.753200000000000
1989-01-01	11.734900000000000
1990-01-01	9.776790000000000
1991-01-01	8.398060000000001
1992-01-01	9.588450000000000
1993-01-01	10.444100000000000
1994-01-01	11.779100000000000
1995-01-01	11.454700000000000
1996-01-01	11.085600000000000
1997-01-01	10.697700000000000
1998-01-01	10.219800000000000
1999-01-01	10.987900000000000
2000-01-01	12.839600000000000
2001-01-01	13.261100000000000
2002-01-01	15.185700000000000
2003-01-01	13.201600000000000
2004-01-01	13.639200000000000
2005-01-01	17.395600000000000
2006-01-01	15.676700000000000
2007-01-01	16.765100000000000
2008-01-01	17.271800000000000
2009-01-01	17.821700000000000
2010-01-01	10.129500000000000
2011-01-01	8.671470000000000
2012-01-01	10.261400000000000
2013-01-01	8.432930000000000
2014-01-01	8.683340000000000
2015-01-01	8.143950000000000
2016-01-01	6.581720000000000