Year	Percent
1960-01-01	1.358695652173910
1961-01-01	1.018766756032150
1962-01-01	1.061571125265410
1963-01-01	1.628151260504200
1964-01-01	1.912144702842390
1965-01-01	2.332657200811340
1966-01-01	3.815659068384560
1967-01-01	3.579952267303070
1968-01-01	4.055299539170530
1969-01-01	4.561558901682910
1970-01-01	3.346039813638280
1971-01-01	2.704918032786880
1972-01-01	4.988028731045500
1973-01-01	7.487647282402130
1974-01-01	10.997171145686000
1975-01-01	10.672188595094000
1976-01-01	7.541738629821520
1977-01-01	7.976445396145620
1978-01-01	8.973723351512150
1979-01-01	9.144676979071900
1980-01-01	10.129220508545200
1981-01-01	12.471612414837300
1982-01-01	10.768971899713900
1983-01-01	5.863588029773660
1984-01-01	4.304778303917360
1985-01-01	3.962030540652080
1986-01-01	4.194786290856170
1987-01-01	4.356108712217400
1988-01-01	4.028234148716110
1989-01-01	4.983621899859590
1990-01-01	4.780476933363050
1991-01-01	5.625864085930040
1992-01-01	1.490132903745450
1993-01-01	1.865079365079360
1994-01-01	0.165562913907281
1995-01-01	2.148760330578520
1996-01-01	1.570531125071370
1997-01-01	1.621216380845280
1998-01-01	0.995942456658074
1999-01-01	1.734842951059180
2000-01-01	2.719439956919720
2001-01-01	2.525120139799070
2002-01-01	2.258394409408560
2003-01-01	2.758563213601120
2004-01-01	1.857258718572610
2005-01-01	2.213552034397640
2006-01-01	2.002025395341560
2007-01-01	2.138383992668430
2008-01-01	2.370270674442940
2009-01-01	0.299466803009284
2010-01-01	1.776871540926290
2011-01-01	2.912135088723550
2012-01-01	1.515678231245210
2013-01-01	0.938291897815210
2014-01-01	1.906635907178730
2015-01-01	1.125241360942790
2016-01-01	1.428759547010800
2017-01-01	1.596884128529700