Year	Percent
1999-01-01	7.58457227346154
2000-01-01	7.05229943408155
2001-01-01	6.34741159995253
2002-01-01	6.15628025277606
2003-01-01	6.11721553699579
2004-01-01	6.06682935843763
2005-01-01	6.98520364832018
2006-01-01	7.14317760340140
2007-01-01	7.13228573007698
2008-01-01	7.66087626031018
2009-01-01	10.27447437320010
2010-01-01	11.61457835050870
2011-01-01	11.07430377206120
2012-01-01	11.34615172495850
2013-01-01	10.22646283956480
2014-01-01	7.56879897769527
2015-01-01	6.62860341814920
2016-01-01	5.12329971318450
2017-01-01	3.81126789087429