Year	Percent
1961-01-01	4.82154000000000000
1962-01-01	11.32540000000000000
1963-01-01	7.51589000000000000
1964-01-01	8.03883999999999900
1965-01-01	10.56740000000000000
1966-01-01	10.51560000000000000
1967-01-01	11.24870000000000000
1968-01-01	10.52910000000000000
1969-01-01	10.47940000000000000
1970-01-01	8.50704000000000000
1971-01-01	14.64510000000000000
1972-01-01	21.00890000000000000
1973-01-01	24.78310000000000000
1974-01-01	22.33960000000000000
1975-01-01	29.83580000000000000
1976-01-01	26.53420000000000000
1977-01-01	23.79220000000000000
1978-01-01	21.40750000000000000
1979-01-01	17.94230000000000000
1980-01-01	15.24590000000000000
1981-01-01	10.83120000000000000
1982-01-01	12.68680000000000000
1983-01-01	18.89920000000000000
1984-01-01	26.59780000000000000
1985-01-01	39.32660000000000000
1986-01-01	48.01399999999999600
1987-01-01	45.06510000000000000
1988-01-01	39.58690000000000000
1989-01-01	31.64030000000000000
1990-01-01	25.82350000000000000
1991-01-01	23.23110000000000000
1992-01-01	20.35360000000000000
1993-01-01	18.87500000000000000
1994-01-01	16.34950000000000000
1995-01-01	13.40330000000000000
1996-01-01	12.57170000000000000
1997-01-01	12.29040000000000000
1998-01-01	12.57830000000000000
1999-01-01	12.67960000000000000
2000-01-01	12.40530000000000000
2001-01-01	12.63370000000000000
2002-01-01	12.38660000000000000
2003-01-01	10.59340000000000000
2004-01-01	7.68948999999999900
2005-01-01	5.43284000000000100
2006-01-01	3.36893000000000000
2007-01-01	2.27326000000000000
2008-01-01	1.95374000000000030
2009-01-01	1.89333000000000000
2010-01-01	1.68120999999999990
2011-01-01	1.54777000000000000
2012-01-01	1.46123000000000000
2013-01-01	1.36052000000000020
2014-01-01	0.92315000000000000
2015-01-01	0.51128300000000000
2016-01-01	0.42839799999999995