Year	Percent
1997-01-01	2.9226200000000000
1998-01-01	2.5735500000000000
1999-01-01	3.4932400000000000
2000-01-01	5.5134700000000000
2001-01-01	5.3092400000000000
2002-01-01	1.9526200000000000
2003-01-01	3.2117100000000000
2004-01-01	4.1784200000000000
2005-01-01	3.4158300000000000
2006-01-01	3.4363200000000000
2007-01-01	3.6415599999999997
2008-01-01	3.3376800000000000
2009-01-01	3.5466100000000000
2010-01-01	2.6852200000000000
2011-01-01	3.9798000000000000
2012-01-01	3.9301800000000005
2013-01-01	2.6340800000000000
2014-01-01	2.7801299999999998
2015-01-01	1.8791700000000000
2016-01-01	2.9055700000000000