Year	Percent
1991-01-01	11.08800029754640
1992-01-01	8.14299964904785
1993-01-01	10.46000003814700
1994-01-01	11.34000015258790
1995-01-01	12.13500022888180
1996-01-01	11.43500041961670
1997-01-01	9.75000000000000
1998-01-01	8.72799968719482
1999-01-01	7.37300014495850
2000-01-01	5.26300001144409
2001-01-01	4.38100004196167
2002-01-01	4.57100009918213
2003-01-01	6.58500003814697
2004-01-01	8.01099967956543
2005-01-01	8.20899963378906
2006-01-01	6.53900003433228
2007-01-01	5.92999982833862
2008-01-01	5.26800012588501
2009-01-01	6.61000013351440
2010-01-01	8.70499992370605
2011-01-01	9.99800014495850
2012-01-01	11.68599987030030
2013-01-01	13.15600013732910
2014-01-01	12.73700046539310
2015-01-01	11.24199962615970
2016-01-01	10.83500003814700
2017-01-01	8.88099956512451