Year	Percent
1991-01-01	47.6080017089844
1992-01-01	47.8940010070801
1993-01-01	47.8339996337891
1994-01-01	48.1669998168945
1995-01-01	46.7169990539551
1996-01-01	47.0900001525879
1997-01-01	47.4589996337891
1998-01-01	47.4790000915527
1999-01-01	47.6399993896484
2000-01-01	47.3549995422363
2001-01-01	46.8349990844727
2002-01-01	46.7459983825684
2003-01-01	46.9360008239746
2004-01-01	47.8180007934570
2005-01-01	48.5699996948242
2006-01-01	50.3650016784668
2007-01-01	50.5779991149902
2008-01-01	50.4819984436035
2009-01-01	50.7830009460449
2010-01-01	51.2280006408691
2011-01-01	51.1580009460449
2012-01-01	50.9690017700195
2013-01-01	50.7410011291504
2014-01-01	51.2120018005371
2015-01-01	51.2649993896484
2016-01-01	52.2820014953613
2017-01-01	52.2410011291504