Year	Percent
1969-01-01	58.5339
1970-01-01	47.5847
1971-01-01	39.0751
1972-01-01	29.1871
1973-01-01	35.9841
1974-01-01	34.6132
1975-01-01	33.7347
1976-01-01	30.7500
1977-01-01	28.4749
1978-01-01	26.4909
1979-01-01	24.3878
1980-01-01	23.5990
1981-01-01	25.9881
1982-01-01	25.2475
1983-01-01	24.7469
1984-01-01	25.1174
1985-01-01	25.6864
1986-01-01	27.3201
1987-01-01	29.2784
1988-01-01	31.5631
1989-01-01	30.1959
1990-01-01	34.1106
1991-01-01	37.1672
1992-01-01	38.8343
1993-01-01	40.8388
1994-01-01	41.8469
1995-01-01	44.4058
1996-01-01	46.4196
1997-01-01	48.3886
1998-01-01	50.3158
1999-01-01	49.6018
2000-01-01	53.6722
2001-01-01	57.8553
2002-01-01	57.1847
2003-01-01	59.1670
2004-01-01	59.4675
2005-01-01	60.3136
2006-01-01	67.3405
2007-01-01	72.0569
2008-01-01	78.0355
2009-01-01	83.9628
2010-01-01	83.1334
2011-01-01	84.3802
2012-01-01	79.4929
2013-01-01	77.1775
2014-01-01	75.8702
2015-01-01	73.6707
2016-01-01	71.8364