Year	Percent
1997-01-01	0.11616199999999999
1998-01-01	0.08146800000000000
1999-01-01	0.07970900000000000
2000-01-01	0.07970900000000000
2001-01-01	0.07970900000000000
2002-01-01	0.07970900000000000
2003-01-01	0.17299400000000000
2004-01-01	0.16935500000000000
2005-01-01	0.14142600000000000
2006-01-01	0.13911400000000002
2007-01-01	0.16888100000000000
2008-01-01	0.16113000000000000
2009-01-01	0.16035500000000000
2010-01-01	0.17295300000000000
2011-01-01	0.18318500000000000
2012-01-01	0.19785899999999998
2013-01-01	0.21719200000000000
2014-01-01	0.25710400000000000
2015-01-01	0.27263699999999996