Year	Percent
1960-01-01	0.360492346844601
1961-01-01	2.155172776709220
1962-01-01	5.274259529207340
1963-01-01	2.471610528964960
1964-01-01	5.867015387519220
1965-01-01	4.187224439980030
1966-01-01	3.250563343053010
1967-01-01	4.579269757540000
1968-01-01	3.448293242542090
1969-01-01	2.962949510752110
1970-01-01	10.637206526418300
1971-01-01	6.223863235012950
1972-01-01	7.258435829615140
1973-01-01	7.419472836375050
1974-01-01	9.411768132118940
1975-01-01	11.689223481685300
1976-01-01	9.161472765475650
1977-01-01	9.103839711602960
1978-01-01	8.161671543396210
1979-01-01	4.509727612062050
1980-01-01	10.878661087866100
1981-01-01	13.642960812772100
1982-01-01	11.340996168582400
1983-01-01	8.465244322092200
1984-01-01	6.218274111675130
1985-01-01	5.714854639585840
1986-01-01	7.176492748163490
1987-01-01	8.717047451669590
1988-01-01	6.676365987714190
1989-01-01	4.546143355053830
1990-01-01	4.131033483113470
1991-01-01	3.438195991091330
1992-01-01	2.328085049118540
1993-01-01	2.288269331930560
1994-01-01	1.375674980714840
1995-01-01	2.460367786937230
1996-01-01	1.262532491644980
1997-01-01	2.566923359002590
1998-01-01	2.252413299964250
1999-01-01	2.365967365967350
2000-01-01	3.085506091312770
2001-01-01	3.004197039982310
2002-01-01	1.286725284151850
2003-01-01	2.487825534617850
2004-01-01	0.454498502220854
2005-01-01	1.532133676092520
2006-01-01	2.329349807575450
2007-01-01	0.712589073634205
2008-01-01	3.753930817610060
2009-01-01	2.197385868535710
2010-01-01	2.418906394810010
2011-01-01	1.284951588091590
2012-01-01	0.696864111498241
2013-01-01	2.120486203531190
2014-01-01	2.041702867072100
2015-01-01	2.171136653895280
2016-01-01	3.550000000000020
2017-01-01	1.875100595525480