Year	Percent
1980-01-01	2.2940700000000000
1981-01-01	1.7839099999999999
1982-01-01	1.1056500000000000
1983-01-01	0.6320290000000000
1984-01-01	0.4637860000000000
1985-01-01	0.5730930000000001
1986-01-01	2.2125200000000000
1987-01-01	4.2879100000000000
1988-01-01	5.0440400000000000
1989-01-01	5.4091100000000000
1990-01-01	4.9583200000000000
1991-01-01	4.1275100000000000
1992-01-01	3.9282900000000000
1993-01-01	4.3822600000000000
1994-01-01	6.8336000000000000
1995-01-01	11.2855000000000000
1996-01-01	7.7632300000000000
1997-01-01	4.9007600000000000
1998-01-01	6.8206300000000000
1999-01-01	6.8979600000000000
2000-01-01	7.6822399999999990
2001-01-01	6.3448400000000005
2002-01-01	4.6131000000000000
2003-01-01	6.7967000000000000
2004-01-01	10.9149000000000000
2005-01-01	14.0982000000000000
2006-01-01	16.0142000000000000
2007-01-01	20.9238000000000000
2008-01-01	20.9729000000000000
2009-01-01	18.4315000000000000
2010-01-01	22.6078000000000000
2011-01-01	22.3391000000000000
2012-01-01	18.2733000000000000
2013-01-01	15.6039000000000000
2014-01-01	12.1808000000000000
2015-01-01	8.9328000000000000
2016-01-01	8.6361500000000000
2017-01-01	11.3978000000000000