Year	Percent
1991-01-01	17.48999977111820
1992-01-01	19.28000068664550
1993-01-01	18.54000091552730
1994-01-01	16.87999916076660
1995-01-01	15.19999980926510
1996-01-01	15.64999961853030
1997-01-01	15.85000038146970
1998-01-01	14.47000026702880
1999-01-01	13.11999988555910
2000-01-01	12.09000015258790
2001-01-01	13.47999954223630
2002-01-01	12.80000019073490
2003-01-01	11.97000026702880
2004-01-01	11.36999988555910
2005-01-01	10.61999988555910
2006-01-01	10.02999973297120
2007-01-01	9.36999988555908
2008-01-01	8.81999969482422
2009-01-01	11.46000003814700
2010-01-01	11.55000019073490
2011-01-01	11.38000011444090
2012-01-01	11.72999954223630
2013-01-01	12.22000026702880
2014-01-01	13.31999969482420
2015-01-01	13.14000034332280
2016-01-01	12.67000007629390
2017-01-01	12.60000038146970
