Year	Percent
1980-01-01	1.3106500000000000
1981-01-01	1.0692100000000000
1982-01-01	2.2108600000000000
1983-01-01	1.6472099999999998
1984-01-01	1.9907200000000000
1985-01-01	3.6939100000000000
1986-01-01	2.9322900000000000
1987-01-01	3.4623500000000000
1988-01-01	3.5584800000000003
1989-01-01	3.9686400000000000
1990-01-01	3.9736200000000000
1991-01-01	4.0901900000000000
1992-01-01	6.0106699999999990
1993-01-01	6.0818400000000010
1994-01-01	8.2002800000000010
1995-01-01	5.2665500000000000
1996-01-01	5.2665500000000000
1997-01-01	5.2665500000000000
1998-01-01	5.2665500000000000
1999-01-01	5.2665500000000000
2000-01-01	5.2665500000000000
2001-01-01	5.2665500000000000
2002-01-01	5.2665500000000000
2003-01-01	10.0675000000000000
2004-01-01	13.2062000000000000
2005-01-01	14.2056000000000000
2006-01-01	15.5478000000000000
2007-01-01	15.9903000000000000
2008-01-01	19.2908000000000000
2009-01-01	19.0792000000000000
2010-01-01	16.4313000000000000
2011-01-01	18.4267000000000000
2012-01-01	19.3057000000000000
2013-01-01	18.7400000000000000
2014-01-01	19.4467000000000000
2015-01-01	22.7674000000000000
2016-01-01	21.1723000000000000
2017-01-01	21.3260000000000000