Year	Percent
1975-01-01	18.31178575399040
1976-01-01	11.54488065198360
1977-01-01	14.89006650232230
1978-01-01	11.45942960213150
1979-01-01	13.67462157591240
1980-01-01	13.60198282894920
1981-01-01	12.29032786059590
1982-01-01	12.09984145180350
1983-01-01	11.48265356012950
1984-01-01	11.11693128578850
1985-01-01	9.40690750687272
1986-01-01	6.85934422794882
1987-01-01	7.63279008878108
1988-01-01	8.35167956821221
1989-01-01	8.04615863487319
1990-01-01	7.54486109699453
1991-01-01	8.93430656934298
1992-01-01	9.48654250617166
1993-01-01	9.52484537019692
1994-01-01	27.44798071269470
1995-01-01	11.42593996466200
1996-01-01	7.19164660433347
1997-01-01	7.64717433310008
1998-01-01	6.43573287560782
1999-01-01	4.35643374510449
2000-01-01	4.50078856262101
2001-01-01	5.18701191944063
2002-01-01	4.70579123746034
2003-01-01	5.67941806432656
2004-01-01	4.13663213144748
2005-01-01	7.10626900078062
2006-01-01	6.38943861721212
2007-01-01	6.54788141133041
2008-01-01	10.55993551760650
2009-01-01	7.37943935240860
2010-01-01	4.02004592890730
2011-01-01	5.36621092948083
2012-01-01	6.58212966194974
2013-01-01	4.93993452674758
2014-01-01	4.40225309243433
2015-01-01	4.04194410725623
2016-01-01	5.55768961400965
2017-01-01	5.31449430117894