Year	Percent
1997-01-01	5198.04
1998-01-01	4397.94
1999-01-01	3837.94
2000-01-01	3246.48
2001-01-01	2964.47
2002-01-01	2752.43
2003-01-01	3679.22
2004-01-01	3349.25
2005-01-01	2675.65
2006-01-01	2577.53
2007-01-01	2321.03
2008-01-01	2296.01
2009-01-01	1942.09
2010-01-01	1939.90
2011-01-01	1660.21
2012-01-01	1557.02
2013-01-01	1270.81