Year	Percent
1991-01-01	17.195999999999998
1992-01-01	18.480000000000000
1993-01-01	17.702900000000000
1994-01-01	15.228800000000000
1995-01-01	13.496900000000000
1996-01-01	11.149100000000000
1997-01-01	11.561900000000000
1998-01-01	12.676700000000000
1999-01-01	11.176100000000000
2000-01-01	8.958269999999999
2001-01-01	8.958269999999999
2002-01-01	8.958269999999999
2003-01-01	8.958269999999999
2004-01-01	12.571200000000000
2005-01-01	11.061200000000000
2006-01-01	17.222200000000000
2007-01-01	27.398200000000000
2008-01-01	34.309800000000000
2009-01-01	45.917900000000000
2010-01-01	40.104700000000000
2011-01-01	33.864700000000000
2012-01-01	31.500500000000000
2013-01-01	30.931700000000000
2014-01-01	31.973500000000000
2015-01-01	38.162600000000000