Year	Percent
1977-01-01	1.7253599999999998
1978-01-01	1.9642300000000000
1979-01-01	2.0216600000000000
1980-01-01	1.9290900000000002
1981-01-01	2.2442599999999997
1982-01-01	2.8244400000000000
1983-01-01	3.3843000000000000
1984-01-01	2.2860099999999997
1985-01-01	2.6224700000000000
1986-01-01	2.8826500000000000
1987-01-01	3.0726700000000000
1988-01-01	3.3310900000000000
1989-01-01	3.1990500000000000
1990-01-01	3.3061300000000005
1991-01-01	4.0733100000000000
1992-01-01	4.7908200000000000
1993-01-01	4.7583100000000000
1994-01-01	5.3866400000000000
1995-01-01	7.2315200000000000
1996-01-01	5.8842600000000000
1997-01-01	8.2568000000000000
1998-01-01	7.1045700000000000
1999-01-01	8.0643300000000000
2000-01-01	8.5453700000000000
2001-01-01	11.4867000000000000
2002-01-01	11.9657000000000000
2003-01-01	12.2026000000000000
2004-01-01	12.5509999999999980
2005-01-01	13.3233000000000000
2006-01-01	12.6798000000000000
2007-01-01	11.0053000000000000
2008-01-01	10.8216000000000000
2009-01-01	11.8570000000000010
2010-01-01	10.8004000000000000
2011-01-01	10.2852000000000000
2012-01-01	9.8402500000000000
2013-01-01	9.8282899999999990
2014-01-01	10.0816000000000000
2015-01-01	10.1783000000000000
2016-01-01	10.2142000000000000
2017-01-01	10.4625000000000000