Year	Percent
1998-01-01	11.84062117250220
1999-01-01	11.42851636568190
2000-01-01	10.58827264052020
2001-01-01	9.52439547069424
2002-01-01	9.00712667033988
2003-01-01	8.67217079938548
2004-01-01	7.99867876604790
2005-01-01	7.72876373472585
2006-01-01	6.77581585774424
2007-01-01	6.07527409054089
2008-01-01	6.72335133693092
2009-01-01	7.74765772612176
2010-01-01	8.35917147367836
2011-01-01	8.35375639028940
2012-01-01	10.65125723176130
2013-01-01	12.14520639257060
2014-01-01	12.67979498355570
2015-01-01	11.89387814161400
2016-01-01	11.68803029749510
2017-01-01	11.21117325242340