Year	Percent
1980-01-01	15.0529
1981-01-01	15.5114
1982-01-01	17.7224
1983-01-01	22.3632
1984-01-01	24.9432
1985-01-01	30.2186
1986-01-01	39.9254
1987-01-01	48.6844
1988-01-01	53.3088
1989-01-01	49.7302
1990-01-01	46.2847
1991-01-01	52.8933
1992-01-01	53.6928
1993-01-01	48.4790
1994-01-01	48.8156
1995-01-01	44.4483
1996-01-01	44.3416
1997-01-01	45.1072
1998-01-01	46.0543
1999-01-01	38.6213
2000-01-01	8.8400
2001-01-01	7.9900
2002-01-01	7.3700
2003-01-01	7.8500
2004-01-01	8.3000
2005-01-01	9.8800
2006-01-01	12.7800
2007-01-01	15.8100
2008-01-01	11.4200
2009-01-01	12.6300
2010-01-01	13.7800
2011-01-01	12.1100
2012-01-01	11.9000
2013-01-01	22.4600
2014-01-01	24.1700
2015-01-01	30.3400
2016-01-01	29.5700