Year	Percent
1980-01-01	2.8453300000000000
1981-01-01	3.4260000000000000
1982-01-01	3.5632500000000000
1983-01-01	3.3781700000000000
1984-01-01	3.2485800000000000
1985-01-01	3.1004200000000000
1986-01-01	3.7035000000000000
1987-01-01	3.4484199999999996
1988-01-01	3.2742500000000000
1989-01-01	3.3173300000000000
1990-01-01	3.3043300000000000
1991-01-01	3.3943300000000000
1992-01-01	2.8001700000000000
1993-01-01	2.8618300000000000
1994-01-01	2.4350000000000000
1995-01-01	2.6043300000000000
1996-01-01	2.3570800000000000
1997-01-01	2.1475000000000000
1998-01-01	2.0550000000000000
1999-01-01	2.0440800000000000
2000-01-01	1.9967500000000000
2001-01-01	1.9123299999999999
2002-01-01	1.8293300000000000
2003-01-01	1.7795800000000000
2004-01-01	1.6863299999999999
2005-01-01	1.4058300000000000
2006-01-01	0.9820830000000000
2007-01-01	1.0750800000000000
2008-01-01	1.3207500000000000
2009-01-01	1.2884200000000001
2010-01-01	1.0982500000000000
2011-01-01	1.0393299999999999
2012-01-01	0.9295000000000000
2013-01-01	0.7615830000000000
2014-01-01	0.8039170000000000
2015-01-01	0.7365830000000000
2016-01-01	0.7443330000000000