Year	Percent
1976-01-01	25.2601
1977-01-01	25.7742
1978-01-01	23.4917
1979-01-01	23.8233
1980-01-01	26.5072
1981-01-01	26.6006
1982-01-01	22.6843
1983-01-01	21.8604
1984-01-01	21.5756
1985-01-01	21.9408
1986-01-01	22.3928
1987-01-01	24.5996
1988-01-01	23.1779
1989-01-01	24.3783
1990-01-01	24.0224
1991-01-01	23.2947
1992-01-01	27.0803
1993-01-01	23.2999
1994-01-01	19.8706
1995-01-01	19.5319
1996-01-01	18.4050
1997-01-01	20.0684
1998-01-01	24.3033
1999-01-01	25.6744
2000-01-01	24.9315
2001-01-01	26.9924
2002-01-01	29.0125
2003-01-01	29.2453
2004-01-01	29.8681
2005-01-01	27.5201
2006-01-01	33.4189
2007-01-01	42.2891
2008-01-01	48.4914
2009-01-01	53.2449
2010-01-01	47.3093
2011-01-01	41.2757
2012-01-01	41.7935
2013-01-01	41.1551
2014-01-01	37.7719
2015-01-01	42.2556
2016-01-01	40.6356