Year	Percent
1998-01-01	10.95677244192850
1999-01-01	9.76172584214855
2000-01-01	9.09051358666149
2001-01-01	8.62369067067010
2002-01-01	9.11341145359590
2003-01-01	9.16223560013174
2004-01-01	8.73037783369292
2005-01-01	8.16700965363425
2006-01-01	7.37941014584468
2007-01-01	6.54095387585838
2008-01-01	6.06626490505717
2009-01-01	8.87117142864055
2010-01-01	9.08876677748468
2011-01-01	8.39777378237553
2012-01-01	8.27608489744289
2013-01-01	8.81694153644754
2014-01-01	9.32193453622258
2015-01-01	9.86912013347444
2016-01-01	9.03330865870370
2017-01-01	8.87271183123826