Year	Percent
1999-01-01	32.7193429867670
2000-01-01	33.2144699994240
2001-01-01	33.2191194897304
2002-01-01	33.3585638568580
2003-01-01	34.1481922857231
2004-01-01	34.0219955101040
2005-01-01	34.1131052434148
2006-01-01	34.2874919326627
2007-01-01	34.1855082413248
2008-01-01	33.9318240598595
2009-01-01	33.4314046278674
2010-01-01	33.9010632164251
2011-01-01	33.9118516321390
2012-01-01	34.8173923316551
2013-01-01	35.1976396447991