Year	Percent
1983-01-01	41.7654
1984-01-01	36.0784
1985-01-01	34.4880
1986-01-01	49.4595
1987-01-01	44.5761
1988-01-01	32.6372
1989-01-01	25.4812
1990-01-01	18.2550
1991-01-01	16.9892
1992-01-01	14.4005
1993-01-01	12.6926
1994-01-01	13.0768
1995-01-01	17.7911
1996-01-01	17.2300
1997-01-01	17.1303
1998-01-01	16.4365
1999-01-01	15.1302
2000-01-01	21.1390
2001-01-01	29.4351
2002-01-01	28.6031
2003-01-01	29.8379
2004-01-01	29.9666
2005-01-01	30.4514
2006-01-01	30.9670
2007-01-01	32.3925
2008-01-01	27.2122
2009-01-01	35.3131
2010-01-01	33.8786
2011-01-01	30.1028
2012-01-01	32.7290
2013-01-01	31.1525
2014-01-01	29.7639
2015-01-01	31.2663
2016-01-01	30.9922