Year	Percent
1975-01-01	11.97475502409530
1976-01-01	11.73242361364200
1977-01-01	13.16872428010790
1978-01-01	9.04398827010364
1979-01-01	11.73623063678850
1980-01-01	13.63242514708950
1981-01-01	16.42802677257120
1982-01-01	11.13720642746890
1983-01-01	10.47714381052370
1984-01-01	8.57746904251907
1985-01-01	8.09457579975941
1986-01-01	10.00171556060220
1987-01-01	9.80193387398672
1988-01-01	8.35167956821221
1989-01-01	11.57501474732850
1990-01-01	11.39634611995570
1991-01-01	11.76501608395340
1992-01-01	16.16761239633390
1993-01-01	14.33080333658880
1994-01-01	10.54292099382170
1995-01-01	10.51254608157910
1996-01-01	10.08285806521080
1997-01-01	8.71993127147747
1998-01-01	6.66139865665754
1999-01-01	7.74929619202846
2000-01-01	8.60148514851490
2001-01-01	6.55903767014864
2002-01-01	8.03279662527484
2003-01-01	9.18990265632737
2004-01-01	6.94570363654676
2005-01-01	8.61022528546438
2006-01-01	11.55521879143790
2007-01-01	7.08099847172692
2008-01-01	12.70218839200760
2009-01-01	8.02729703109585
2010-01-01	6.94887658743105
2011-01-01	8.45987233408587
2012-01-01	7.53690261091916
2013-01-01	5.88460707056813
2014-01-01	4.40225309243433
2015-01-01	3.06203169580559
2016-01-01	2.81495791361942
2017-01-01	3.30828076768221