Year	Percent
1964-01-01	10.282800000000000
1965-01-01	8.718780000000000
1966-01-01	8.403440000000000
1967-01-01	9.122440000000000
1968-01-01	12.220600000000000
1969-01-01	9.950800000000000
1970-01-01	6.381030000000000
1971-01-01	5.842370000000000
1972-01-01	6.526940000000000
1973-01-01	6.931960000000001
1974-01-01	6.962680000000001
1975-01-01	6.969700000000000
1976-01-01	7.479170000000000
1977-01-01	8.035890000000000
1978-01-01	9.671640000000000
1979-01-01	8.240910000000001
1980-01-01	7.897310000000001
1981-01-01	8.703280000000000
1982-01-01	9.383330000000000
1983-01-01	9.967900000000000
1984-01-01	12.402200000000000
1985-01-01	11.961300000000000
1986-01-01	12.652600000000000
1987-01-01	10.241100000000000
1988-01-01	11.248100000000000
1989-01-01	10.865600000000000
1990-01-01	10.325800000000000
1991-01-01	10.194100000000000
1992-01-01	11.441300000000000
1993-01-01	12.104800000000000
1994-01-01	11.895000000000000
1995-01-01	12.245800000000000
1996-01-01	12.269400000000000
1997-01-01	12.907200000000000
1998-01-01	13.797200000000000
1999-01-01	14.475200000000000
2000-01-01	16.301900000000000
2001-01-01	16.974500000000000
2002-01-01	19.225400000000000
2003-01-01	19.924100000000000
2004-01-01	21.657500000000000
2005-01-01	24.496400000000000
2006-01-01	28.559300000000000
2007-01-01	31.717700000000000
2008-01-01	33.802600000000000
2009-01-01	36.617200000000000
2010-01-01	39.334800000000000
2011-01-01	44.634700000000000
2012-01-01	42.996300000000000
2013-01-01	42.427000000000000
2014-01-01	43.944200000000000