Year	Percent
1986-01-01	3.73560887291676
1987-01-01	3.27696292786685
1988-01-01	4.23294095978688
1989-01-01	5.26750684100621
1990-01-01	5.48823554331432
1991-01-01	7.66521079577025
1992-01-01	7.83026774693068
1993-01-01	7.14012739387848
1994-01-01	6.12739825815934
1995-01-01	5.16463530875922
1996-01-01	5.17016688761838
1997-01-01	5.49330973261016
1998-01-01	6.40498827627457
1999-01-01	5.52828197711196
2000-01-01	4.78542118612789
2001-01-01	4.23185011356731
2002-01-01	4.30544542091930
2003-01-01	4.02270660053942
2004-01-01	3.46751368401927
2005-01-01	3.10114211926332
2006-01-01	2.98757732533547
2007-01-01	2.89408629383797
2008-01-01	3.12897635532386
2009-01-01	4.17513005655928
2010-01-01	4.99409529301310
2011-01-01	5.06877624095974
2012-01-01	5.43489172037840
2013-01-01	5.25516053660876
2014-01-01	5.19942334632824
2015-01-01	4.89661276626154
2016-01-01	4.47554733885852
2017-01-01	4.23262505115250