Year	Percent
1960-01-01	6.971089999999999
1961-01-01	11.649000000000001
1962-01-01	11.472300000000000
1963-01-01	11.891600000000000
1964-01-01	6.846230000000000
1965-01-01	6.562440000000000
1966-01-01	6.282420000000000
1967-01-01	5.986930000000000
1968-01-01	12.056400000000000
1969-01-01	6.293700000000000
1970-01-01	10.397600000000000
1971-01-01	10.347700000000000
1972-01-01	10.367600000000000
1973-01-01	9.567269999999999
1974-01-01	10.349100000000000
1975-01-01	10.360300000000000
1976-01-01	11.799900000000000
1977-01-01	12.725200000000000
1978-01-01	13.883900000000000
1979-01-01	19.258400000000000
1980-01-01	18.472900000000000
1981-01-01	12.210700000000000
1982-01-01	12.207000000000000
1983-01-01	12.207000000000000
1984-01-01	15.732100000000000
1985-01-01	16.651200000000000
1986-01-01	17.056100000000000
1987-01-01	18.049400000000000
1988-01-01	15.838900000000000
1989-01-01	14.321500000000000
1990-01-01	14.423600000000000
1991-01-01	14.556100000000000
1992-01-01	14.172100000000000
1993-01-01	11.834400000000000
1994-01-01	8.503800000000000
1995-01-01	9.573560000000000
1996-01-01	11.690200000000000
1997-01-01	11.797800000000000
1998-01-01	9.969640000000000
1999-01-01	9.507390000000000
2000-01-01	9.790880000000000
2001-01-01	9.844270000000000
2002-01-01	10.905500000000000
2003-01-01	10.373800000000000
2004-01-01	7.058660000000001
2005-01-01	6.584650000000000
2006-01-01	8.978280000000000
2007-01-01	9.538190000000000
2008-01-01	9.867160000000000
2009-01-01	11.387600000000000
2010-01-01	10.392400000000000
2011-01-01	10.475000000000000
2012-01-01	11.611400000000000
2013-01-01	12.677800000000000
2014-01-01	13.834900000000000
2015-01-01	16.462400000000000