Year	Percent
1960-01-01	1.955034213098730
1965-01-01	1.179673321234120
1967-01-01	1.221640488656200
1969-01-01	1.126516464471400
1970-01-01	0.728987993138936
1971-01-01	1.141649048625790
1972-01-01	0.966792770071459
1973-01-01	0.872817955112219
1974-01-01	3.602128530495290
1975-01-01	4.932735426008970
1976-01-01	6.409736308316430
1977-01-01	7.419226166733150
1978-01-01	8.375933936295710
1979-01-01	6.047765793528500
1980-01-01	6.932931424265260
1981-01-01	10.434782608695700
1982-01-01	11.086142322097400
1983-01-01	9.743647487144840
1984-01-01	8.867049469964660
1985-01-01	7.795650121636830
1986-01-01	6.032614488222550
1987-01-01	6.090247036984150
1988-01-01	6.486806790058910
1989-01-01	8.150295072807900
1990-01-01	8.338222605694560
1991-01-01	9.100003449584320
1992-01-01	9.026292181353940
1993-01-01	10.719627143403700
1994-01-01	8.036393953673830
1995-01-01	7.038227938549480
1996-01-01	6.909992912827780
1997-01-01	6.094570928196150
1998-01-01	5.442415730337080
1999-01-01	5.586689864398180
2000-01-01	4.625902947431320
2001-01-01	4.607074403206130
2002-01-01	4.586738134650590
2003-01-01	5.406727401364350
2004-01-01	5.507578960082130
2005-01-01	4.829577379563120
2006-01-01	3.896715625401450
2007-01-01	3.800888675393300
2008-01-01	3.433247579717010
2009-01-01	6.006785411365560
2010-01-01	7.463069347558470
2011-01-01	7.572350703201810
2012-01-01	7.525494849438510
2013-01-01	6.996098379659670
2014-01-01	6.589113937120340
2015-01-01	6.168756446209840
2016-01-01	6.180670846032490
2017-01-01	5.742663732438560