Year	Percent
1999-01-01	6.86922299248989
2000-01-01	7.92049756625203
2001-01-01	8.10852182682611
2002-01-01	8.03918743696874
2003-01-01	7.67332973167657
2004-01-01	8.37400358062667
2005-01-01	7.38700053631790
2006-01-01	6.29574874698013
2007-01-01	5.42108494443955
2008-01-01	4.73124807080347
2009-01-01	5.50255189512436
2010-01-01	6.33666860669716
2011-01-01	5.83420662739855
2012-01-01	6.28471470821611
2013-01-01	6.33175970305236