Year	Percent
1991-01-01	10.0122883198993
1992-01-01	10.0305933520139
1993-01-01	10.3702907140163
1994-01-01	10.5118455176080
1995-01-01	10.5752847235350
1996-01-01	10.8360956611542
1997-01-01	11.1157404762612
1998-01-01	11.4732963480008
1999-01-01	11.6300407471227
2000-01-01	11.7264803389107
2001-01-01	11.6448518761740
2002-01-01	11.2380957385293
2003-01-01	11.0810173577374
2004-01-01	11.5456282069598
2005-01-01	11.4556186224985
2006-01-01	11.1388241823480
2007-01-01	11.1809005395898
2008-01-01	11.1711662760742
2009-01-01	11.1821752801437
2010-01-01	10.5708779723172
2011-01-01	10.4561757697502
2012-01-01	10.2986356251423
2013-01-01	10.4879760111731
2014-01-01	10.3935112485873
2015-01-01	10.6654990120556
2016-01-01	10.7741937887774
2017-01-01	10.8620248292021