Year	Percent
1966-01-01	3.17752100842009
1967-01-01	1.82404343794972
1968-01-01	3.44942509524235
1969-01-01	3.20554123770314
1970-01-01	1.84953956571386
1971-01-01	2.32166117555597
1972-01-01	2.36633218489992
1973-01-01	11.54352596964350
1974-01-01	19.28777544569610
1975-01-01	12.04574193216780
1976-01-01	6.53091265949245
1977-01-01	20.80512182762000
1978-01-01	8.51761476291619
1979-01-01	16.45351697007620
1980-01-01	18.68397540349560
1981-01-01	20.05579665225400
1982-01-01	10.80742134184120
1983-01-01	11.56752438340690
1984-01-01	12.93972664127260
1985-01-01	20.46263345195760
1986-01-01	13.73707533234870
1987-01-01	13.37662337662280
1988-01-01	20.39456227811150
1989-01-01	7.54616477272769
1990-01-01	13.09228991249800
1991-01-01	8.93430656934298
1992-01-01	7.55829536317330
1993-01-01	12.02342387241480
1994-01-01	13.76932488043590
1995-01-01	12.28859126014260
1996-01-01	6.42521330315215
1997-01-01	7.12532722513055
1998-01-01	8.10996563573864
1999-01-01	6.08886063431494
2000-01-01	12.20853585458440
2001-01-01	5.94210982281648
2002-01-01	12.01971546992310
2003-01-01	7.28999999999999
2004-01-01	3.44533507316615
2005-01-01	4.77400404553712
2006-01-01	5.30463946338725
2007-01-01	8.07608827861561
2008-01-01	12.65746018639160
2009-01-01	7.44823423445763
2010-01-01	4.50923691774356
2011-01-01	6.10742714590276
2012-01-01	8.93960918520304
2013-01-01	5.62091576250522
2014-01-01	5.68134885776450
2015-01-01	4.95124493704912
2016-01-01	7.84727459085686
2017-01-01	6.22127934981429