Year	Percent
1977-01-01	11.191001637035800
1978-01-01	8.855345912140900
1980-01-01	14.492874406452100
1981-01-01	12.413261372398000
1982-01-01	7.276408617798570
1983-01-01	5.589498018439470
1984-01-01	5.403808859577350
1985-01-01	4.819731648779680
1986-01-01	4.766141331977630
1987-01-01	4.089116446412130
1988-01-01	4.858859178140480
1989-01-01	6.189354033823540
1990-01-01	7.725321888412080
1991-01-01	6.257526632700200
1992-01-01	5.138897799448260
1993-01-01	4.271538107369340
1994-01-01	3.611358001478360
1995-01-01	5.182205395172730
1996-01-01	3.050161812297980
1997-01-01	3.605344443646270
1998-01-01	3.274445542604650
1999-01-01	2.926613927446070
2000-01-01	3.311426432987330
2001-01-01	3.380184673728180
2002-01-01	2.407658012934340
2003-01-01	2.621395249001730
2004-01-01	3.094850858853470
2005-01-01	3.679875599303220
2006-01-01	4.246109912947760
2007-01-01	4.965976545533000
2008-01-01	8.758727695887970
2009-01-01	2.795512835504110
2010-01-01	3.207443440015830
2011-01-01	4.805389221556870
2012-01-01	3.656620482788200
2013-01-01	1.923436041083090
2014-01-01	1.638250905098950
2015-01-01	0.961100058801496
2016-01-01	1.129801632668980
2017-01-01	1.698920782240910