Year	Percent
1998-01-01	15.78
1999-01-01	18.19
2000-01-01	17.58
2001-01-01	17.59
2002-01-01	25.19
2003-01-01	27.16
2004-01-01	24.95
2005-01-01	30.53
2006-01-01	28.47
2007-01-01	28.21
2008-01-01	26.89
2009-01-01	28.60
2010-01-01	27.98
2011-01-01	28.49
2012-01-01	30.31
2013-01-01	29.81
2014-01-01	31.15
2015-01-01	30.18
2016-01-01	29.79