Year	Percent
1991-01-01	52.2288
1992-01-01	54.7372
1993-01-01	52.6936
1994-01-01	47.4490
1995-01-01	51.7693
1996-01-01	51.7314
1997-01-01	48.5767
1998-01-01	48.5283
1999-01-01	52.2655
2000-01-01	51.1637
2001-01-01	51.9339
2002-01-01	55.7036
2003-01-01	58.9639
2004-01-01	56.5462
2005-01-01	56.5661
2006-01-01	57.2409
2007-01-01	54.0237
2008-01-01	58.5327
2009-01-01	69.1565
2010-01-01	71.3015
2011-01-01	69.1655
2012-01-01	73.2304
2013-01-01	72.6944
2014-01-01	70.6591
2015-01-01	74.8891