Year	Percent
1980-01-01	2.5847400000000000
1981-01-01	2.5539800000000000
1982-01-01	2.2498700000000000
1983-01-01	1.9479500000000000
1984-01-01	1.8157700000000000
1985-01-01	1.7554500000000000
1986-01-01	1.7197200000000001
1987-01-01	2.3048400000000000
1988-01-01	2.4693900000000000
1989-01-01	3.5286199999999996
1990-01-01	37.0359000000000000
1991-01-01	33.6461000000000000
1992-01-01	31.0362000000000000
1993-01-01	33.8705000000000000
1994-01-01	34.1009000000000000
1995-01-01	25.4091000000000000
1996-01-01	27.0973000000000000
1997-01-01	27.4805000000000000
1998-01-01	22.5490000000000000
1999-01-01	21.3469000000000000
2000-01-01	16.3616000000000000
2001-01-01	16.2703000000000000
2002-01-01	20.6363000000000000
2003-01-01	23.7295000000000000
2004-01-01	18.6925000000000000
2005-01-01	17.4554000000000000
2006-01-01	12.1088000000000000
2007-01-01	13.1544000000000000
2008-01-01	9.2075500000000000
2009-01-01	11.6037000000000000
2010-01-01	11.0293000000000000
2011-01-01	16.0567000000000000
2012-01-01	13.4037000000000000
2013-01-01	12.1432000000000000
2014-01-01	8.5001000000000000