Year	Percent
1997-01-01	8.35339
1998-01-01	8.18295
1999-01-01	11.15420
2000-01-01	15.22140
2001-01-01	17.31950
2002-01-01	18.64080
2003-01-01	18.78460
2004-01-01	17.99180
2005-01-01	13.41620
2006-01-01	10.85120
2007-01-01	10.38910
2008-01-01	7.51245
2009-01-01	11.75460
2010-01-01	12.38590
2011-01-01	13.74700
2012-01-01	20.33050
2013-01-01	26.66730
2014-01-01	26.71330
2015-01-01	32.99590
2016-01-01	30.44670