Year	Percent
1960-01-01	7.5531500000000000
1961-01-01	6.6277700000000000
1962-01-01	7.1001699999999990
1963-01-01	8.8461500000000000
1964-01-01	6.8282899999999990
1965-01-01	7.0767399999999990
1966-01-01	7.8103800000000000
1967-01-01	8.3331699999999990
1968-01-01	8.7620000000000000
1969-01-01	9.0639500000000000
1970-01-01	3.0302400000000000
1971-01-01	2.9994600000000000
1972-01-01	3.2005300000000000
1973-01-01	3.8102099999999997
1974-01-01	4.8872500000000000
1975-01-01	6.1409600000000000
1976-01-01	9.0728800000000000
1977-01-01	13.7645000000000000
1978-01-01	16.0289000000000000
1979-01-01	12.7047000000000000
1980-01-01	11.0749000000000000
1981-01-01	11.2974000000000000
1982-01-01	11.7405000000000000
1983-01-01	12.1853000000000000
1984-01-01	13.0711000000000000
1985-01-01	14.1559999999999990
1986-01-01	14.2841000000000000
1987-01-01	18.5426000000000000
1988-01-01	14.9445000000000000
1989-01-01	13.8837000000000000
1990-01-01	12.6612000000000000
1991-01-01	13.5080000000000000
1992-01-01	12.8045000000000000
1993-01-01	11.5303000000000000
1994-01-01	9.8595899999999990
1995-01-01	9.6710900000000000
1996-01-01	8.9795900000000000
1997-01-01	9.9472000000000000
1998-01-01	12.2482000000000000
1999-01-01	11.0009000000000000
2000-01-01	9.7549500000000000
2001-01-01	11.6313000000000000
2002-01-01	12.2501000000000000
2003-01-01	12.4275000000000000
2004-01-01	11.9793000000000000
2005-01-01	11.7686000000000000
2006-01-01	12.9663000000000000
2007-01-01	13.2794000000000000
2008-01-01	12.3657000000000000
2009-01-01	15.5991000000000000
2010-01-01	14.5044000000000000
2011-01-01	15.3920000000000010
2012-01-01	17.6376000000000000
2013-01-01	18.8794000000000000
2014-01-01	19.2354000000000000
2015-01-01	19.9115000000000000
2016-01-01	20.1171000000000000