Year	Percent
1983-01-01	47.5742
1984-01-01	41.7322
1985-01-01	43.1619
1986-01-01	37.0671
1987-01-01	36.9564
1988-01-01	33.0269
1989-01-01	34.2716
1990-01-01	29.5849
1991-01-01	26.6756
1992-01-01	22.7026
1993-01-01	19.8811
1994-01-01	25.4165
1995-01-01	23.0180
1996-01-01	17.2994
1997-01-01	26.9405
1998-01-01	23.4062
1999-01-01	25.8067
2000-01-01	28.9259
2001-01-01	32.5127
2002-01-01	34.2758
2003-01-01	35.9845
2004-01-01	31.5988
2005-01-01	26.6317
2006-01-01	32.3523
2007-01-01	32.3688
2008-01-01	25.3623
2009-01-01	16.8386
2010-01-01	16.2631
2011-01-01	18.4692
2012-01-01	15.4049
2013-01-01	13.6932
2014-01-01	12.5090
2015-01-01	15.4551
2016-01-01	15.5834