Year	Percent
1971-01-01	20.052224104987900
1972-01-01	77.795733773312500
1973-01-01	352.811007014665000
1974-01-01	504.738522505321000
1975-01-01	374.735269459445000
1976-01-01	211.924280160440000
1977-01-01	91.954136727531700
1978-01-01	40.087241666005000
1979-01-01	33.389207240443200
1980-01-01	35.138347811969100
1981-01-01	19.686829636522500
1982-01-01	9.941020666420590
1983-01-01	27.257198454033700
1984-01-01	19.860209061059500
1985-01-01	30.703520901490000
1986-01-01	19.476847293518900
1987-01-01	19.880801233253400
1988-01-01	14.684352571779100
1989-01-01	17.027955738640700
1990-01-01	26.036472159678000
1991-01-01	21.784417376175100
1992-01-01	15.425805597341900
1993-01-01	12.727761039437400
1994-01-01	11.443120537664700
1995-01-01	8.232633317762570
1996-01-01	7.359117443570800
1997-01-01	6.133866369871860
1998-01-01	5.110243016190770
1999-01-01	3.336885341370240
2000-01-01	3.843273290112190
2001-01-01	3.569101680000860
2002-01-01	2.489394542705590
2003-01-01	2.810178611932350
2004-01-01	1.054738756505150
2005-01-01	3.052576581998840
2006-01-01	3.392017382845220
2007-01-01	4.407799046155090
2008-01-01	8.716267366466330
2009-01-01	0.353046309419725
2010-01-01	1.410809606373010
2011-01-01	3.340317435523260
2012-01-01	3.006520589954770
2013-01-01	1.928220312547920
2014-01-01	4.395000000000000
2015-01-01	4.348867282915850
2016-01-01	3.786661770780740
2017-01-01	2.182469485229090