Year	Percent
1980-01-01	8.273450000000000
1981-01-01	8.743269999999999
1982-01-01	7.898580000000000
1983-01-01	10.479700000000000
1984-01-01	9.516410000000000
1985-01-01	11.215300000000000
1986-01-01	13.627800000000000
1987-01-01	15.729400000000000
1988-01-01	14.285500000000000
1989-01-01	15.199200000000000
1990-01-01	11.966100000000000
1991-01-01	10.065300000000000
1992-01-01	13.739300000000000
1993-01-01	15.169000000000000
1994-01-01	15.487200000000000
1995-01-01	14.890600000000000
1996-01-01	13.303900000000000
1997-01-01	15.716400000000000
1998-01-01	14.597900000000000
1999-01-01	13.454200000000000
2000-01-01	14.950200000000000
2001-01-01	19.872200000000000
2002-01-01	20.123500000000000
2003-01-01	18.926400000000000
2004-01-01	17.273500000000000
2005-01-01	18.838000000000000
2006-01-01	18.948800000000000
2007-01-01	17.940500000000000
2008-01-01	17.935300000000000
2009-01-01	18.325200000000000
2010-01-01	16.787600000000000
2011-01-01	18.670600000000000
2012-01-01	21.802100000000000
2013-01-01	23.959100000000000
2014-01-01	22.978800000000000
2015-01-01	22.552000000000000
2016-01-01	22.261999999999997