Year	Percent
1980-01-01	1.7315099999999999
1981-01-01	1.4598700000000000
1982-01-01	1.1692600000000000
1983-01-01	1.1632600000000000
1984-01-01	2.6242799999999997
1985-01-01	4.7780000000000005
1986-01-01	8.5066200000000000
1987-01-01	13.3307000000000000
1988-01-01	14.8248000000000000
1989-01-01	13.2406000000000000
1990-01-01	9.3239399999999990
1991-01-01	8.7744400000000000
1992-01-01	6.3238100000000000
1993-01-01	8.3049800000000000
1994-01-01	5.9583300000000000
1995-01-01	5.6062000000000000
1996-01-01	7.2270900000000000
1997-01-01	5.5420300000000005
1998-01-01	5.2627600000000000
1999-01-01	7.9638700000000000
2000-01-01	7.9422399999999990
2001-01-01	7.4934500000000000
2002-01-01	7.3861800000000000
2003-01-01	5.9783100000000000
2004-01-01	5.0261300000000000
2005-01-01	4.1292700000000000
2006-01-01	2.8192900000000000
2007-01-01	3.0751700000000000
2008-01-01	2.2804300000000000
2009-01-01	2.0761300000000000
2010-01-01	1.7515400000000000
2011-01-01	1.5235100000000001
2012-01-01	1.5377000000000000
2013-01-01	3.5358300000000003
2014-01-01	3.4790400000000004
2015-01-01	3.9846100000000000
2016-01-01	9.1131500000000000