Year	Percent
1960-01-01	19.561400000000000
1961-01-01	19.483700000000000
1962-01-01	18.693400000000000
1963-01-01	18.129800000000000
1964-01-01	17.900300000000000
1965-01-01	17.784200000000000
1966-01-01	16.715999999999998
1967-01-01	16.281400000000000
1968-01-01	17.449900000000000
1969-01-01	18.051800000000000
1970-01-01	15.514100000000000
1971-01-01	13.869100000000000
1972-01-01	13.546600000000000
1973-01-01	12.223400000000000
1974-01-01	11.350800000000000
1975-01-01	13.310400000000000
1976-01-01	13.710400000000000
1977-01-01	14.096200000000000
1978-01-01	14.983100000000000
1979-01-01	14.524900000000000
1980-01-01	12.148900000000000
1981-01-01	14.775900000000000
1982-01-01	15.961300000000000
1983-01-01	20.037200000000000
1984-01-01	18.572800000000000
1985-01-01	16.336900000000000
1986-01-01	18.999800000000000
1987-01-01	17.168700000000000
1988-01-01	15.243700000000000
1989-01-01	11.334000000000001
1990-01-01	10.938300000000000
1991-01-01	10.936800000000000
1992-01-01	11.464500000000000
1993-01-01	13.342400000000000
1994-01-01	17.890100000000000
1995-01-01	22.181900000000000
1996-01-01	23.383700000000000
1997-01-01	23.655100000000000
1998-01-01	24.812900000000000
1999-01-01	29.511600000000000
2000-01-01	30.187400000000000
2001-01-01	22.569600000000000
2002-01-01	19.662300000000000
2003-01-01	16.546500000000000
2004-01-01	16.812800000000000
2005-01-01	18.341700000000000
2006-01-01	19.520000000000000
2007-01-01	20.595300000000000
2008-01-01	20.651200000000000
2009-01-01	22.337200000000000
2010-01-01	22.243500000000000
2011-01-01	23.439300000000000
2012-01-01	24.588200000000000
2013-01-01	25.300800000000000
2014-01-01	25.903200000000000
2015-01-01	27.501500000000000
2016-01-01	28.590700000000000