Year	Percent
1960-01-01	2.26687099162787
1961-01-01	3.10525014675918
1962-01-01	2.07669528411571
1963-01-01	2.51476028420785
1964-01-01	3.67911884891220
1965-01-01	2.74593248798561
1966-01-01	2.87319422160330
1967-01-01	2.55439473084728
1968-01-01	3.25356740941592
1969-01-01	2.44186116813624
1970-01-01	4.30390335201463
1971-01-01	4.31393562108009
1972-01-01	5.18569212724151
1973-01-01	13.22618137109810
1974-01-01	23.55268738502770
1975-01-01	15.36298568512630
1976-01-01	9.79365327534655
1977-01-01	10.68895742077510
1978-01-01	10.50795993431870
1979-01-01	14.84230816553280
1980-01-01	18.12638988161540
1981-01-01	14.03191956173240
1982-01-01	7.72949223911318
1983-01-01	10.91288721853990
1984-01-01	11.72891520703460
1985-01-01	20.50758317628270
1986-01-01	16.89666805446990
1987-01-01	14.06471111585070
1988-01-01	13.41739741196520
1989-01-01	14.75150357271520
1990-01-01	22.64137077657750
1991-01-01	25.09640730934920
1992-01-01	13.62653368300050
1993-01-01	11.28416844549890
1994-01-01	12.19478312370600
1995-01-01	12.53595945589630
1996-01-01	11.05691653219870
1997-01-01	7.14511160883933
1998-01-01	7.24782175213469
1999-01-01	5.95423949113011
2000-01-01	7.05702729099890
2001-01-01	6.60404780032071
2002-01-01	5.28219145568432
2003-01-01	5.79222744750472
2004-01-01	4.67843566370074
2005-01-01	5.22212358740886
2006-01-01	4.28948758877541
2007-01-01	6.28492294859285
2008-01-01	9.23353362925650
2009-01-01	2.91335842849470
2010-01-01	3.85950909833189
2011-01-01	5.12892376681616
2012-01-01	4.11150854557409
2013-01-01	2.81650282055419
2014-01-01	3.51847818195019
2015-01-01	3.12900274473923
2016-01-01	2.72461223295292
2017-01-01	3.27955694678546