Year	Percent
1980-01-01	13.533381276113400
1981-01-01	11.427176323054900
1982-01-01	8.885713084714600
1983-01-01	6.908228811588470
1984-01-01	5.991951110484450
1985-01-01	4.641880542871940
1986-01-01	2.933579204423340
1987-01-01	3.664563217516890
1988-01-01	4.402411827867620
1989-01-01	5.076793427742660
1990-01-01	5.400955211126880
1991-01-01	4.948192749796220
1992-01-01	3.947711768240330
1993-01-01	4.042852910769430
1994-01-01	2.693056456846200
1995-01-01	2.956800250926210
1996-01-01	2.456575682382120
1997-01-01	2.336862983141120
1998-01-01	1.869488536155410
1999-01-01	1.699151450568160
2000-01-01	2.579876112186120
2001-01-01	2.578440800988940
2002-01-01	1.989983382380500
2003-01-01	2.021685428579990
2004-01-01	2.142089646402420
2005-01-01	2.487696651640860
2006-01-01	2.495874931248920
2007-01-01	2.756723716381380
2008-01-01	4.541818379817230
2009-01-01	1.371422646666440
2010-01-01	1.813536280336810
2011-01-01	3.335090748635230
2012-01-01	2.710563855309570
2013-01-01	1.471559406257590
2014-01-01	1.033089370006450
2015-01-01	0.292704628136101
2016-01-01	0.528651720979176
2017-01-01	1.596884128529700