Year	Percent
1964-01-01	21.533500000000000
1965-01-01	19.605800000000000
1966-01-01	19.149800000000000
1967-01-01	19.523500000000000
1968-01-01	25.575500000000000
1969-01-01	21.166500000000000
1970-01-01	14.451900000000000
1971-01-01	14.173400000000000
1972-01-01	14.666600000000000
1973-01-01	16.592700000000000
1974-01-01	17.085200000000000
1975-01-01	15.444400000000000
1976-01-01	14.645300000000000
1977-01-01	12.927300000000000
1978-01-01	14.748200000000000
1979-01-01	13.913100000000000
1980-01-01	13.654200000000000
1981-01-01	14.331400000000000
1982-01-01	16.016900000000000
1983-01-01	16.562200000000000
1984-01-01	19.159400000000000
1985-01-01	18.111300000000000
1986-01-01	19.038400000000000
1987-01-01	14.768800000000000
1988-01-01	15.747000000000000
1989-01-01	15.333000000000000
1990-01-01	14.720600000000000
1991-01-01	14.403100000000000
1992-01-01	15.906400000000000
1993-01-01	16.693200000000000
1994-01-01	16.172400000000000
1995-01-01	16.666200000000000
1996-01-01	16.743300000000000
1997-01-01	18.057600000000000
1998-01-01	19.255800000000000
1999-01-01	19.599800000000000
2000-01-01	22.223300000000000
2001-01-01	23.022000000000000
2002-01-01	25.673500000000000
2003-01-01	26.696600000000000
2004-01-01	29.235500000000000
2005-01-01	32.475400000000000
2006-01-01	37.665600000000000
2007-01-01	41.025400000000000
2008-01-01	42.000900000000000
2009-01-01	44.583100000000000
2010-01-01	46.999900000000000
2011-01-01	53.028400000000000
2012-01-01	51.861999999999995
2013-01-01	51.832200000000000
2014-01-01	53.659800000000000