Year	Percent
1999-01-01	32.2907088122605
2000-01-01	32.9651640519004
2001-01-01	32.5794618375070
2002-01-01	32.8563427877131
2003-01-01	33.1522972206466
2004-01-01	33.6124904706342
2005-01-01	34.5540222242146
2006-01-01	34.7755918254318
2007-01-01	35.7474302693365
2008-01-01	36.3466376929768
2009-01-01	36.1740948841342
2010-01-01	36.5760698506851
2011-01-01	36.5621908991937
2012-01-01	36.5188270400486
2013-01-01	36.7180041475942
2014-01-01	37.0469150218248