Year	Percent
1980-01-01	22.1656000000000000
1981-01-01	23.7461000000000000
1982-01-01	24.1334000000000000
1983-01-01	19.9141000000000000
1984-01-01	20.6347000000000000
1985-01-01	16.1419000000000000
1986-01-01	11.6419000000000000
1987-01-01	18.4278000000000000
1988-01-01	8.8576000000000000
1989-01-01	6.5719000000000000
1990-01-01	6.7269000000000000
1991-01-01	6.7861600000000010
1992-01-01	7.0677600000000010
1993-01-01	10.3169000000000000
1994-01-01	9.8249400000000000
1995-01-01	9.3291100000000000
1996-01-01	9.0672300000000000
1997-01-01	6.7137600000000010
1998-01-01	5.0256400000000000
1999-01-01	3.8810500000000000
2000-01-01	4.0905000000000000
2001-01-01	3.8193599999999996
2002-01-01	4.7682300000000000
2003-01-01	4.1208000000000000
2004-01-01	3.9754199999999997
2005-01-01	6.0965300000000004
2006-01-01	5.1337100000000000
2007-01-01	6.2525400000000000
2008-01-01	5.7856800000000000
2009-01-01	5.7578200000000000
2010-01-01	6.6882600000000005
2011-01-01	5.1406800000000010
2012-01-01	6.0292300000000000
2013-01-01	6.5433699999999995
2014-01-01	6.3079700000000000
2015-01-01	5.6355400000000000
2016-01-01	5.2891200000000000