Year	Percent
1966-01-01	0.08531500000000000
1967-01-01	0.27368400000000004
1968-01-01	0.26522100000000000
1969-01-01	0.23318699999999998
1970-01-01	0.20497200000000000
1971-01-01	0.40344400000000000
1972-01-01	1.75617000000000000
1973-01-01	1.93943000000000000
1974-01-01	2.12234000000000030
1975-01-01	2.47070000000000000
1976-01-01	4.11881999999999950
1977-01-01	5.75684000000000000
1978-01-01	7.08383000000000000
1979-01-01	6.94081999999999950
1980-01-01	7.79866000000000100
1981-01-01	9.80320000000000000
1982-01-01	10.52920000000000000
1983-01-01	12.27310000000000000
1984-01-01	17.13220000000000000
1985-01-01	19.12590000000000000
1986-01-01	22.03710000000000000
1987-01-01	24.81030000000000000
1988-01-01	23.43430000000000000
1989-01-01	25.20699999999999700
1990-01-01	22.78090000000000000
1991-01-01	19.12520000000000000
1992-01-01	15.06390000000000000
1993-01-01	20.35470000000000000
1994-01-01	18.54990000000000000
1995-01-01	15.63350000000000000
1996-01-01	14.89450000000000000
1997-01-01	15.28890000000000000
1998-01-01	14.40570000000000000
1999-01-01	14.27980000000000000
2000-01-01	15.29740000000000000
2001-01-01	16.44080000000000000
2002-01-01	16.41330000000000000
2003-01-01	19.78900000000000000
2004-01-01	20.32000000000000000
2005-01-01	24.08960000000000000
2006-01-01	29.46320000000000000
2007-01-01	37.58930000000000000
2008-01-01	39.48820000000000000
2009-01-01	53.98740000000000000
2010-01-01	49.15260000000000000
2011-01-01	46.59640000000000000
2012-01-01	52.11360000000000000
2013-01-01	48.47570000000000000
2014-01-01	41.84780000000000000
2015-01-01	46.57540000000000000
2016-01-01	45.33760000000000000