Year	Percent
1970-01-01	4.124178563335680
1971-01-01	9.138193688791990
1972-01-01	21.978504057907000
1973-01-01	11.085318206340100
1974-01-01	14.498469507888200
1975-01-01	13.064880982982400
1976-01-01	11.432436426468800
1977-01-01	7.006304449839310
1978-01-01	6.108071005015020
1979-01-01	7.806758249521170
1980-01-01	14.492874406452100
1981-01-01	11.180666763762100
1982-01-01	7.031556893894820
1983-01-01	6.704183998014210
1984-01-01	5.291217610724280
1985-01-01	4.420972396219140
1986-01-01	1.798842484338040
1987-01-01	5.663774758552170
1988-01-01	11.758326878388900
1989-01-01	6.189354033823540
1990-01-01	8.191371320409710
1991-01-01	6.497345559845460
1992-01-01	4.883022715686130
1993-01-01	5.206589251957660
1994-01-01	0.816666666667021
1995-01-01	2.165647214415360
1996-01-01	3.050161812297980
1997-01-01	3.368140064379410
1998-01-01	5.711681604131220
1999-01-01	1.968673660009180
2000-01-01	1.092164599773890
2001-01-01	4.272670244651030
2002-01-01	0.762032085561235
2003-01-01	4.172747777630330
2004-01-01	2.827485193912020
2005-01-01	2.365764538304350
2006-01-01	2.490836387870780
2007-01-01	4.803706413069890
2008-01-01	7.732278579184230
2009-01-01	3.214695752009100
2010-01-01	3.680014831294030
2011-01-01	7.282401406422250
2012-01-01	3.408333764201390
2013-01-01	2.916290183569980
2014-01-01	0.528118153039539
2015-01-01	1.376130952512180
2016-01-01	3.864771417595080
2017-01-01	3.351087438970260