Year	Percent
1960-01-01	22.166000000000000
1961-01-01	22.348400000000000
1962-01-01	23.804500000000000
1963-01-01	24.457200000000000
1964-01-01	24.238800000000000
1965-01-01	25.014400000000000
1966-01-01	24.526700000000000
1967-01-01	24.729700000000000
1968-01-01	25.099100000000000
1969-01-01	26.004700000000000
1970-01-01	22.895000000000000
1971-01-01	24.110000000000000
1972-01-01	24.272200000000000
1973-01-01	23.900600000000000
1974-01-01	22.992300000000000
1975-01-01	23.304300000000000
1976-01-01	26.263700000000000
1977-01-01	25.977700000000000
1978-01-01	24.055999999999997
1979-01-01	24.701400000000000
1980-01-01	24.328400000000000
1981-01-01	25.376300000000000
1982-01-01	23.964300000000000
1983-01-01	22.354100000000000
1984-01-01	21.974100000000000
1985-01-01	20.553100000000000
1986-01-01	19.830300000000000
1987-01-01	16.319600000000000
1988-01-01	13.067300000000000
1989-01-01	11.416900000000000
1990-01-01	16.073100000000000
1991-01-01	20.257300000000000
1992-01-01	23.049300000000000
1993-01-01	22.255400000000000
1994-01-01	22.878700000000000
1995-01-01	23.502700000000000
1996-01-01	21.680700000000000
1997-01-01	24.431800000000000
1998-01-01	26.532500000000000
1999-01-01	26.329800000000000
2000-01-01	23.849400000000000
2001-01-01	22.489100000000000
2002-01-01	22.355800000000000
2003-01-01	22.993600000000000
2004-01-01	22.806300000000000
2005-01-01	23.378100000000000
2006-01-01	23.254700000000000
2007-01-01	24.174600000000000
2008-01-01	25.158700000000000
2009-01-01	26.378600000000000
2010-01-01	25.163000000000000
2011-01-01	25.351900000000000
2012-01-01	25.849100000000000
2013-01-01	26.970700000000000
2014-01-01	27.602800000000000
2015-01-01	28.722200000000000
2016-01-01	29.398600000000000