Year	Percent
1983-01-01	31.4256
1984-01-01	29.5482
1985-01-01	31.3135
1986-01-01	26.1181
1987-01-01	18.4701
1988-01-01	13.0470
1989-01-01	11.4697
1990-01-01	12.1805
1991-01-01	12.4544
1992-01-01	12.6607
1993-01-01	12.3691
1994-01-01	14.0545
1995-01-01	15.4331
1996-01-01	18.0583
1997-01-01	17.6901
1998-01-01	20.4165
1999-01-01	16.3879
2000-01-01	13.6055
2001-01-01	13.6417
2002-01-01	14.1691
2003-01-01	15.2244
2004-01-01	20.9001
2005-01-01	24.5223
2006-01-01	28.5529
2007-01-01	33.3614
2008-01-01	29.8816
2009-01-01	37.6258
2010-01-01	31.0443
2011-01-01	27.5489
2012-01-01	27.0253
2013-01-01	22.3004
2014-01-01	20.8266
2015-01-01	18.6595
2016-01-01	17.9427