Year	Percent
1999-01-01	25.9969711465208
2000-01-01	27.8897158321756
2001-01-01	29.1016987893286
2002-01-01	30.4798853239085
2003-01-01	31.7581366149804
2004-01-01	33.1237513848228
2005-01-01	35.1986802952424
2006-01-01	36.5041786759420
2007-01-01	37.5400071531762
2008-01-01	37.6478056886552
2009-01-01	36.0701190242775
2010-01-01	35.5794378771448
2011-01-01	35.2905386347944
2012-01-01	34.1888584803814
2013-01-01	33.4081096145763
2014-01-01	33.8149851533621