Year	Percent
1997-01-01	7.1833000000000000
1998-01-01	3.7806200000000000
1999-01-01	2.4614800000000000
2000-01-01	3.5121800000000003
2001-01-01	7.4752300000000010
2002-01-01	4.4407000000000000
2003-01-01	6.2537600000000000
2004-01-01	6.9911800000000000
2005-01-01	7.5606100000000005
2006-01-01	5.6953300000000000
2007-01-01	6.8080300000000005
2008-01-01	6.5543500000000000
2009-01-01	5.5598300000000010
2010-01-01	7.2219000000000000
2011-01-01	6.9752000000000000
2012-01-01	5.1903400000000000
2013-01-01	4.7511100000000000
2014-01-01	4.5503100000000000
2015-01-01	4.9875400000000000
2016-01-01	5.9674300000000000