Year	Percent
1976-01-01	2.9838100000000000
1977-01-01	2.5140800000000000
1978-01-01	2.6130200000000000
1979-01-01	3.7071600000000000
1980-01-01	3.5642199999999997
1981-01-01	3.5917400000000000
1982-01-01	3.3732800000000003
1983-01-01	2.3264200000000000
1984-01-01	3.1134600000000000
1985-01-01	6.9278400000000000
1986-01-01	4.0478200000000000
1987-01-01	3.6659699999999997
1988-01-01	4.0200500000000000
1989-01-01	4.7332900000000000
1990-01-01	4.9801600000000000
1991-01-01	4.4532099999999994
1992-01-01	6.1061000000000000
1993-01-01	4.4254500000000000
1994-01-01	9.6343800000000000
1995-01-01	9.7739000000000000
1996-01-01	9.3688899999999990
1997-01-01	8.5384300000000000
1998-01-01	8.4615000000000000
1999-01-01	8.7555000000000000
2000-01-01	9.7681200000000000
2001-01-01	11.4033000000000000
2002-01-01	12.8077000000000000
2003-01-01	14.6775000000000000
2004-01-01	15.7738000000000000
2005-01-01	15.7226000000000000
2006-01-01	16.1583000000000000
2007-01-01	16.5477000000000000
2008-01-01	15.7661000000000000
2009-01-01	15.6950000000000000
2010-01-01	15.3616000000000000
2011-01-01	14.5819000000000000
2012-01-01	14.6494000000000000
2013-01-01	15.2146000000000000
2014-01-01	16.3249000000000000
2015-01-01	16.6438000000000000
2016-01-01	17.3112000000000000
2017-01-01	17.0761000000000000