Year	Percent
1991-01-01	46.5130004882813
1992-01-01	46.4659996032715
1993-01-01	46.3370018005371
1994-01-01	46.4560012817383
1995-01-01	46.1800003051758
1996-01-01	46.1619987487793
1997-01-01	46.2960014343262
1998-01-01	46.1829986572266
1999-01-01	46.0219993591309
2000-01-01	46.1389999389648
2001-01-01	45.9640007019043
2002-01-01	45.8440017700195
2003-01-01	45.6100006103516
2004-01-01	45.4630012512207
2005-01-01	45.2620010375977
2006-01-01	45.0800018310547
2007-01-01	45.0769996643066
2008-01-01	44.9760017395020
2009-01-01	44.8839988708496
2010-01-01	44.6759986877441
2011-01-01	44.5540008544922
2012-01-01	44.4189987182617
2013-01-01	44.4059982299805
2014-01-01	44.4199981689453
2015-01-01	44.5219993591309
2016-01-01	44.5480003356934
2017-01-01	44.5340003967285