Year	Percent
1991-01-01	35.4819984436035
1992-01-01	33.8769989013672
1993-01-01	36.8300018310547
1994-01-01	40.7589988708496
1995-01-01	35.4729995727539
1996-01-01	37.0050010681152
1997-01-01	26.5769996643066
1998-01-01	26.9610004425049
1999-01-01	23.5750007629395
2000-01-01	21.2740001678467
2001-01-01	24.1569995880127
2002-01-01	25.2439994812012
2003-01-01	20.3840007781982
2004-01-01	21.7789993286133
2005-01-01	15.1260004043579
2006-01-01	13.6049995422363
2007-01-01	10.5520000457764
2008-01-01	13.6429996490479
2009-01-01	33.3689994812012
2010-01-01	36.1220016479492
2011-01-01	30.9750003814697
2012-01-01	28.5009994506836
2013-01-01	23.2070007324219
2014-01-01	19.5779991149902
2015-01-01	16.2730007171631
2016-01-01	17.2250003814697
2017-01-01	16.9799995422363