Year	Percent
1997-01-01	2.556340933
1998-01-01	0.777232885
1999-01-01	0.737770617
2000-01-01	1.004878879
2001-01-01	1.918151140
2002-01-01	3.101022243
2003-01-01	3.932093859
2004-01-01	4.026422024
2005-01-01	3.281911135
2006-01-01	2.591851234
2007-01-01	2.177705050
2008-01-01	1.785920143
2009-01-01	2.098743439
2010-01-01	2.317393541
2011-01-01	2.713223696
2012-01-01	4.754991055
2013-01-01	7.485084057