Year	Percent
1998-01-01	9.11726304950526
1999-01-01	8.77645954514239
2000-01-01	8.13756082232622
2001-01-01	7.33551499673844
2002-01-01	6.95292240786543
2003-01-01	6.77860507376024
2004-01-01	6.31250986977961
2005-01-01	6.16779100427400
2006-01-01	5.42164268618820
2007-01-01	4.87893759760299
2008-01-01	5.49584673311656
2009-01-01	6.72458690414656
2010-01-01	7.49490419607524
2011-01-01	7.51549784779434
2012-01-01	9.80146519666259
2013-01-01	11.47609554753940
2014-01-01	11.86019501722780
2015-01-01	11.31651256433880
2016-01-01	10.89055511802160
2017-01-01	10.33920571364630