Year	Percent
1960-01-01	4.154821779821600
1961-01-01	1.595633004527220
1962-01-01	5.796652201013760
1963-01-01	5.625549370088140
1964-01-01	8.183079057003400
1965-01-01	2.564102564284410
1966-01-01	5.399999999680830
1967-01-01	6.253953193977330
1968-01-01	2.358806458905960
1969-01-01	1.955510322853850
1970-01-01	14.381461675732800
1971-01-01	21.403343536614300
1972-01-01	8.204034134988330
1973-01-01	16.580032263846400
1974-01-01	34.163591635916600
1975-01-01	6.761402704560760
1976-01-01	9.199227136110110
1977-01-01	9.898751597365650
1978-01-01	7.334525939176900
1979-01-01	17.533333332750200
1980-01-01	18.200510493850900
1981-01-01	13.082598524167600
1982-01-01	10.221727137689100
1983-01-01	10.029356562048100
1984-01-01	50.338975637449800
1985-01-01	23.103107180388800
1986-01-01	1.148137776533330
1987-01-01	4.069767441860290
1988-01-01	13.860069167331800
1989-01-01	12.242990654205500
1990-01-01	12.177352206494600
1991-01-01	19.261458526628200
1992-01-01	8.651003578652640
1993-01-01	6.716311041099730
1994-01-01	10.386473429951800
1995-01-01	6.831996109895310
1996-01-01	7.476103777879080
1997-01-01	5.590259396506020
1998-01-01	9.234934322671200
1999-01-01	5.939049017808070
2000-01-01	3.977125032492800
2001-01-01	5.345501955671400
2002-01-01	2.722772277227690
2003-01-01	2.289156626506060
2004-01-01	4.829210836277960
2005-01-01	6.516853932584310
2006-01-01	5.485232067510530
2007-01-01	2.900000000000020
2008-01-01	8.260447035957240
2009-01-01	4.219030520646270
2010-01-01	3.789836347975910
2011-01-01	4.718417047184160
2012-01-01	3.026963911247980
2013-01-01	2.582687661417970
2014-01-01	3.597823438642070
2015-01-01	0.674192536845412
2016-01-01	1.253698800809830
2017-01-01	2.853187725909420