Year	Percent
1979-01-01	0.3520120000000000
1980-01-01	0.4066460000000000
1981-01-01	0.7526750000000000
1982-01-01	0.6772300000000000
1983-01-01	0.7108949999999999
1984-01-01	0.9009670000000000
1985-01-01	2.4231900000000000
1986-01-01	2.3056000000000000
1987-01-01	2.2932799999999998
1988-01-01	2.0408800000000000
1989-01-01	1.9437700000000000
1990-01-01	1.6414000000000000
1991-01-01	1.3859400000000000
1992-01-01	1.4811400000000000
1993-01-01	1.5982800000000000
1994-01-01	1.6239800000000000
1995-01-01	1.6600700000000002
1996-01-01	1.5662700000000000
1997-01-01	1.6539599999999999
1998-01-01	1.5614900000000000
1999-01-01	1.1946600000000000
2000-01-01	2.5711700000000000
2001-01-01	4.6734300000000010
2002-01-01	5.3946200000000000
2003-01-01	5.3408000000000000
2004-01-01	6.3303400000000005
2005-01-01	6.7622200000000000
2006-01-01	6.5938500000000000
2007-01-01	5.3810600000000000
2008-01-01	4.1638900000000000
2009-01-01	5.9653700000000000
2010-01-01	5.5930400000000000
2011-01-01	4.2483300000000000
2012-01-01	4.7987699999999990
2013-01-01	4.8585199999999995
2014-01-01	4.9285500000000000
2015-01-01	5.7581000000000000
2016-01-01	5.7609300000000000
2017-01-01	5.4125800000000000