Year	Percent
1980-01-01	5.9892000000000000
1981-01-01	4.4645900000000000
1982-01-01	5.5107099999999996
1983-01-01	5.9916900000000000
1984-01-01	7.3755500000000000
1985-01-01	9.9517000000000000
1986-01-01	8.7288700000000000
1987-01-01	7.9228800000000000
1988-01-01	9.9263000000000000
1989-01-01	7.7459200000000000
1990-01-01	9.2893900000000000
1991-01-01	9.5729000000000000
1992-01-01	10.9289000000000000
1993-01-01	8.5444400000000000
1994-01-01	6.6610500000000000
1995-01-01	4.4830800000000000
1996-01-01	3.2879699999999996
1997-01-01	3.4378900000000003
1998-01-01	4.1431700000000000
1999-01-01	6.2283900000000000
2000-01-01	6.0394100000000000
2001-01-01	7.3824300000000000
2002-01-01	6.9732000000000000
2003-01-01	6.4532300000000005
2004-01-01	4.5522700000000000
2005-01-01	4.1214300000000000
2006-01-01	2.2722300000000000
2007-01-01	2.1474599999999997
2008-01-01	2.8308900000000000
2009-01-01	6.7781100000000010
2010-01-01	8.3175300000000000