Year	Percent
1998-01-01	7.000
1999-01-01	8.700
2000-01-01	9.050
2001-01-01	8.100
2002-01-01	7.800
2003-01-01	5.750
2004-01-01	4.200
2005-01-01	3.500
2006-01-01	3.100
2007-01-01	2.700
2008-01-01	3.000
2009-01-01	4.300
2010-01-01	4.670
2011-01-01	4.160
2012-01-01	4.125
2013-01-01	4.490
2014-01-01	4.205
2015-01-01	4.405