Year	Percent
1960-01-01	9.822410812978820
1961-01-01	3.162564395857380
1962-01-01	0.721320571656314
1963-01-01	0.371849607221678
1964-01-01	3.814489572230420
1965-01-01	2.154374835209680
1966-01-01	-0.388148532154474
1967-01-01	1.597610079643590
1968-01-01	0.690360521996206
1969-01-01	3.593194515512830
1970-01-01	1.666870939700660
1971-01-01	4.195298372654230
1972-01-01	6.398241351288760
1973-01-01	9.819486733187600
1974-01-01	14.248935538256800
1975-01-01	12.879181833834100
1976-01-01	11.256142506211100
1977-01-01	27.287784679309300
1978-01-01	11.721969204121200
1979-01-01	10.487236727348600
1980-01-01	20.643914437379800
1981-01-01	24.203589762448600
1982-01-01	18.689725926956400
1983-01-01	19.740189177861100
1984-01-01	12.540219453886900
1985-01-01	4.389340957415360
1986-01-01	18.429003021147500
1987-01-01	28.571428571429100
1988-01-01	28.670634920634500
1989-01-01	22.349653045489700
1990-01-01	7.627674937639340
1991-01-01	17.128567943401100
1992-01-01	25.807722616233100
1993-01-01	21.202630754776100
1994-01-01	31.447028423772800
1995-01-01	49.655985846274700
1996-01-01	28.937344016813600
1997-01-01	17.349225753870800
1998-01-01	17.866134213039700
1999-01-01	20.070707814686700
2000-01-01	14.476751318856500
2001-01-01	11.274247133211700
2002-01-01	14.335933737840400
2003-01-01	16.468011624479200
2004-01-01	14.761508697067300
2005-01-01	13.433118008507900
2006-01-01	11.939552197344100
2007-01-01	17.213046352581400
2008-01-01	25.549844609132200
2009-01-01	13.500261817489600
2010-01-01	10.137147171077100
2011-01-01	20.628332063975600
2012-01-01	26.454771000405100
2013-01-01	39.266360983743200
2014-01-01	17.235358675047400
2015-01-01	13.705799753202000
2016-01-01	8.582255442710870
2017-01-01	10.481233675574200