Year	Percent
1991-01-01	48.9780006408691
1992-01-01	48.9889984130859
1993-01-01	48.9669990539551
1994-01-01	48.9420013427734
1995-01-01	48.9249992370605
1996-01-01	49.0040016174316
1997-01-01	49.0719985961914
1998-01-01	48.7099990844727
1999-01-01	48.3569984436035
2000-01-01	48.0439987182617
2001-01-01	47.7280006408691
2002-01-01	47.4760017395020
2003-01-01	47.1879997253418
2004-01-01	46.8930015563965
2005-01-01	48.5989990234375
2006-01-01	50.2439994812012
2007-01-01	51.4860000610352
2008-01-01	53.9959983825684
2009-01-01	56.5149993896484
2010-01-01	59.7140007019043
2011-01-01	62.0909996032715
2012-01-01	63.4830017089844
2013-01-01	64.7669982910156
2014-01-01	66.7310028076172
2015-01-01	65.7470016479492
2016-01-01	65.6429977416992
2017-01-01	65.8450012207031